从排序的链表中删除重复项
编写一个函数，该函数接受一个按非递减顺序排序的列表，并从列表中删除任何重复的节点。该列表应该只被遍历一次。
例如，如果链表是 11->11->11->21->43->43->60，那么 removeDuplicates() 应该将列表转换为 11->21->43->60。
算法：
从头（或开始）节点遍历列表。在遍历时，将每个节点与其下一个节点进行比较。如果下一个节点的数据与当前节点相同，则删除下一个节点。在我们删除一个节点之前，我们需要存储该节点的下一个指针
执行：
removeDuplicates() 以外的函数只是创建一个链表并测试 removeDuplicates()。
C++
/* C++ Program to remove duplicates from a sorted linked list */
#include
using namespace std;
/* Link list node */
class Node
{
public:
int data;
Node* next;
};
/* The function removes duplicates from a sorted list */
void removeDuplicates(Node* head)
{
/* Pointer to traverse the linked list */
Node* current = head;
/* Pointer to store the next pointer of a node to be deleted*/
Node* next_next;
/* do nothing if the list is empty */
if (current == NULL)
return;
/* Traverse the list till last node */
while (current->next != NULL)
{
/* Compare current node with next node */
if (current->data == current->next->data)
{
/* The sequence of steps is important*/
next_next = current->next->next;
free(current->next);
current->next = next_next;
}
else /* This is tricky: only advance if no deletion */
{
current = current->next;
}
}
}
/* UTILITY FUNCTIONS */
/* Function to insert a node at the beginning of the linked list */
void push(Node** head_ref, int new_data)
{
/* allocate node */
Node* new_node = new Node();
/* put in the data */
new_node->data = new_data;
/* link the old list off the new node */
new_node->next = (*head_ref);
/* move the head to point to the new node */
(*head_ref) = new_node;
}
/* Function to print nodes in a given linked list */
void printList(Node *node)
{
while (node!=NULL)
{
cout<<" "<data;
node = node->next;
}
}
/* Driver program to test above functions*/
int main()
{
/* Start with the empty list */
Node* head = NULL;
/* Let us create a sorted linked list to test the functions
Created linked list will be 11->11->11->13->13->20 */
push(&head, 20);
push(&head, 13);
push(&head, 13);
push(&head, 11);
push(&head, 11);
push(&head, 11);
cout<<"Linked list before duplicate removal ";
printList(head);
/* Remove duplicates from linked list */
removeDuplicates(head);
cout<<"\nLinked list after duplicate removal ";
printList(head);
return 0;
}
// This code is contributed by rathbhupendra C
/* C Program to remove duplicates from a sorted linked list */
#include
#include
/* Link list node */
struct Node
{
int data;
struct Node* next;
};
/* The function removes duplicates from a sorted list */
void removeDuplicates(struct Node* head)
{
/* Pointer to traverse the linked list */
struct Node* current = head;
/* Pointer to store the next pointer of a node to be deleted*/
struct Node* next_next;
/* do nothing if the list is empty */
if (current == NULL)
return;
/* Traverse the list till last node */
while (current->next != NULL)
{
/* Compare current node with next node */
if (current->data == current->next->data)
{
/* The sequence of steps is important*/
next_next = current->next->next;
free(current->next);
current->next = next_next;
}
else /* This is tricky: only advance if no deletion */
{
current = current->next;
}
}
}
/* UTILITY FUNCTIONS */
/* Function to insert a node at the beginning of the linked list */
void push(struct Node** head_ref, int new_data)
{
/* allocate node */
struct Node* new_node =
(struct Node*) malloc(sizeof(struct Node));
/* put in the data */
new_node->data = new_data;
/* link the old list off the new node */
new_node->next = (*head_ref);
/* move the head to point to the new node */
(*head_ref) = new_node;
}
/* Function to print nodes in a given linked list */
void printList(struct Node *node)
{
while (node!=NULL)
{
printf("%d ", node->data);
node = node->next;
}
}
/* Driver program to test above functions*/
int main()
{
/* Start with the empty list */
struct Node* head = NULL;
/* Let us create a sorted linked list to test the functions
Created linked list will be 11->11->11->13->13->20 */
push(&head, 20);
push(&head, 13);
push(&head, 13);
push(&head, 11);
push(&head, 11);
push(&head, 11);
printf("\n Linked list before duplicate removal ");
printList(head);
/* Remove duplicates from linked list */
removeDuplicates(head);
printf("\n Linked list after duplicate removal ");
printList(head);
return 0;
} Java
// Java program to remove duplicates from a sorted linked list
class LinkedList
{
Node head; // head of list
/* Linked list Node*/
class Node
{
int data;
Node next;
Node(int d) {data = d; next = null; }
}
void removeDuplicates()
{
/*Another reference to head*/
Node curr = head;
/* Traverse list till the last node */
while (curr != null) {
Node temp = curr;
/*Compare current node with the next node and
keep on deleting them until it matches the current
node data */
while(temp!=null && temp.data==curr.data) {
temp = temp.next;
}
/*Set current node next to the next different
element denoted by temp*/
curr.next = temp;
curr = curr.next;
}
}
/* Utility functions */
/* Inserts a new Node at front of the list. */
public void push(int new_data)
{
/* 1 & 2: Allocate the Node &
Put in the data*/
Node new_node = new Node(new_data);
/* 3. Make next of new Node as head */
new_node.next = head;
/* 4. Move the head to point to new Node */
head = new_node;
}
/* Function to print linked list */
void printList()
{
Node temp = head;
while (temp != null)
{
System.out.print(temp.data+" ");
temp = temp.next;
}
System.out.println();
}
/* Driver program to test above functions */
public static void main(String args[])
{
LinkedList llist = new LinkedList();
llist.push(20);
llist.push(13);
llist.push(13);
llist.push(11);
llist.push(11);
llist.push(11);
System.out.println("List before removal of duplicates");
llist.printList();
llist.removeDuplicates();
System.out.println("List after removal of elements");
llist.printList();
}
}
/* This code is contributed by Rajat Mishra */Python3
# Python3 program to remove duplicate
# nodes from a sorted linked list
# Node class
class Node:
# Constructor to initialize
# the node object
def __init__(self, data):
self.data = data
self.next = None
class LinkedList:
# Function to initialize head
def __init__(self):
self.head = None
# Function to insert a new node
# at the beginning
def push(self, new_data):
new_node = Node(new_data)
new_node.next = self.head
self.head = new_node
# Given a reference to the head of a
# list and a key, delete the first
# occurrence of key in linked list
def deleteNode(self, key):
# Store head node
temp = self.head
# If head node itself holds the
# key to be deleted
if (temp is not None):
if (temp.data == key):
self.head = temp.next
temp = None
return
# Search for the key to be deleted,
# keep track of the previous node as
# we need to change 'prev.next'
while(temp is not None):
if temp.data == key:
break
prev = temp
temp = temp.next
# if key was not present in
# linked list
if(temp == None):
return
# Unlink the node from linked list
prev.next = temp.next
temp = None
# Utility function to print the
# linked LinkedList
def printList(self):
temp = self.head
while(temp):
print(temp.data , end = ' ')
temp = temp.next
# This function removes duplicates
# from a sorted list
def removeDuplicates(self):
temp = self.head
if temp is None:
return
while temp.next is not None:
if temp.data == temp.next.data:
new = temp.next.next
temp.next = None
temp.next = new
else:
temp = temp.next
return self.head
# Driver Code
llist = LinkedList()
llist.push(20)
llist.push(13)
llist.push(13)
llist.push(11)
llist.push(11)
llist.push(11)
print ("Created Linked List: ")
llist.printList()
print()
print("Linked List after removing",
"duplicate elements:")
llist.removeDuplicates()
llist.printList()
# This code is contributed by
# Dushyant Pathak.C#
// C# program to remove duplicates
// from a sorted linked list
using System;
public class LinkedList
{
Node head; // head of list
/* Linked list Node*/
class Node
{
public int data;
public Node next;
public Node(int d)
{
data = d; next = null;
}
}
void removeDuplicates()
{
/*Another reference to head*/
Node current = head;
/* Pointer to store the next
pointer of a node to be deleted*/
Node next_next;
/* do nothing if the list is empty */
if (head == null)
return;
/* Traverse list till the last node */
while (current.next != null)
{
/*Compare current node with the next node */
if (current.data == current.next.data)
{
next_next = current.next.next;
current.next = null;
current.next = next_next;
}
else // advance if no deletion
current = current.next;
}
}
/* Utility functions */
/* Inserts a new Node at front of the list. */
public void push(int new_data)
{
/* 1 & 2: Allocate the Node &
Put in the data*/
Node new_node = new Node(new_data);
/* 3. Make next of new Node as head */
new_node.next = head;
/* 4. Move the head to point to new Node */
head = new_node;
}
/* Function to print linked list */
void printList()
{
Node temp = head;
while (temp != null)
{
Console.Write(temp.data+" ");
temp = temp.next;
}
Console.WriteLine();
}
/* Driver code */
public static void Main(String []args)
{
LinkedList llist = new LinkedList();
llist.push(20);
llist.push(13);
llist.push(13);
llist.push(11);
llist.push(11);
llist.push(11);
Console.WriteLine("List before removal of duplicates");
llist.printList();
llist.removeDuplicates();
Console.WriteLine("List after removal of elements");
llist.printList();
}
}
/* This code is contributed by 29AjayKumar */Javascript
C++
/* C++ Program to remove duplicates
from a sorted linked list */
#include
using namespace std;
/* Link list node */
class Node
{
public:
int data;
Node* next;
};
/* The function removes duplicates
from a sorted list */
void removeDuplicates(Node* head)
{
/* Pointer to store the pointer of a node to be deleted*/
Node* to_free;
/* do nothing if the list is empty */
if (head == NULL)
return;
/* Traverse the list till last node */
if (head->next != NULL)
{
/* Compare head node with next node */
if (head->data == head->next->data)
{
/* The sequence of steps is important.
to_free pointer stores the next of head
pointer which is to be deleted.*/
to_free = head->next;
head->next = head->next->next;
free(to_free);
removeDuplicates(head);
}
else /* This is tricky: only
advance if no deletion */
{
removeDuplicates(head->next);
}
}
}
/* UTILITY FUNCTIONS */
/* Function to insert a node at the
beginning of the linked list */
void push(Node** head_ref, int new_data)
{
/* allocate node */
Node* new_node = new Node();
/* put in the data */
new_node->data = new_data;
/* link the old list off the new node */
new_node->next = (*head_ref);
/* move the head to point to the new node */
(*head_ref) = new_node;
}
/* Function to print nodes
in a given linked list */
void printList(Node *node)
{
while (node!=NULL)
{
cout<<" "<data;
node = node->next;
}
}
/* Driver code*/
int main()
{
/* Start with the empty list */
Node* head = NULL;
/* Let us create a sorted linked
list to test the functions
Created linked list will be
11->11->11->13->13->20 */
push(&head, 20);
push(&head, 13);
push(&head, 13);
push(&head, 11);
push(&head, 11);
push(&head, 11);
cout<<"Linked list before duplicate removal ";
printList(head);
/* Remove duplicates from linked list */
removeDuplicates(head);
cout<<"\nLinked list after duplicate removal ";
printList(head);
return 0;
}
// This code is contributed by Ashita Gupta C
/* C recursive Program to remove duplicates from a sorted linked list */
#include
#include
/* Link list node */
struct Node
{
int data;
struct Node* next;
};
/* UTILITY FUNCTIONS */
/* Function to insert a node at the beginning of the linked list */
void push(struct Node** head_ref, int new_data)
{
/* allocate node */
struct Node* new_node =
(struct Node*) malloc(sizeof(struct Node));
/* put in the data */
new_node->data = new_data;
/* link the old list off the new node */
new_node->next = (*head_ref);
/* move the head to point to the new node */
(*head_ref) = new_node;
}
/* Function to print nodes in a given linked list */
void printList(struct Node *node)
{
while (node!=NULL)
{
printf("%d ", node->data);
node = node->next;
}
}
Node* deleteDuplicates(Node* head) {
if (head == nullptr) return nullptr;
if (head->next == nullptr) return head;
if (head->data == head->next->data) {
Node *tmp;
// If find next element duplicate, preserve the next pointer to be deleted,
// skip it, and then delete the stored one. Return head
tmp = head->next;
head->next = head->next->next;
free(tmp);
return deleteDuplicates(head);
}
else {
// if doesn't find next element duplicate, leave head
// and check from next element
head->next = deleteDuplicates(head->next);
return head;
}
}
int main()
{
/* Start with the empty list */
struct Node* head = NULL;
/* Let us create a sorted linked list to test the functions
Created linked list will be 11->11->11->13->13->20 */
push(&head, 20);
push(&head, 13);
push(&head, 13);
push(&head, 11);
push(&head, 11);
push(&head, 11);
printf("\n Linked list before duplicate removal ");
printList(head);
/* Remove duplicates from linked list */
head = deleteDuplicates(head);
printf("\n Linked list after duplicate removal ");
printList(head);
return 0;
}
/* This code is contributed by Yogesh shukla */ Java
// Java Program to remove duplicates
// from a sorted linked list
class GFG
{
/* Link list node */
static class Node
{
int data;
Node next;
};
// The function removes duplicates
// from a sorted list
static Node removeDuplicates(Node head)
{
/* Pointer to store the pointer
of a node to be deleted*/
Node to_free;
/* do nothing if the list is empty */
if (head == null)
return null;
/* Traverse the list till last node */
if (head.next != null)
{
/* Compare head node with next node */
if (head.data == head.next.data)
{
/* The sequence of steps is important.
to_free pointer stores the next of head
pointer which is to be deleted.*/
to_free = head.next;
head.next = head.next.next;
removeDuplicates(head);
}
/* This is tricky: only advance if no deletion */
else
{
removeDuplicates(head.next);
}
}
return head;
}
/* UTILITY FUNCTIONS */
/* Function to insert a node at the beginning
of the linked list */
static Node push(Node head_ref,
int new_data)
{
/* allocate node */
Node new_node = new Node();
/* put in the data */
new_node.data = new_data;
/* link the old list off the new node */
new_node.next = (head_ref);
/* move the head to point to the new node */
(head_ref) = new_node;
return head_ref;
}
/* Function to print nodes in a given linked list */
static void printList(Node node)
{
while (node != null)
{
System.out.print(" " + node.data);
node = node.next;
}
}
/* Driver code*/
public static void main(String args[])
{
/* Start with the empty list */
Node head = null;
/* Let us create a sorted linked list
to test the functions
Created linked list will be 11.11.11.13.13.20 */
head = push(head, 20);
head = push(head, 13);
head = push(head, 13);
head = push(head, 11);
head = push(head, 11);
head = push(head, 11);
System.out.println("Linked list before" +
" duplicate removal ");
printList(head);
/* Remove duplicates from linked list */
head = removeDuplicates(head);
System.out.println("\nLinked list after" +
" duplicate removal ");
printList(head);
}
}
// This code is contributed by Arnab KunduPython3
# Python3 Program to remove duplicates
# from a sorted linked list
import math
# Link list node
class Node:
def __init__(self,data):
self.data = data
self.next = None
# The function removes duplicates
# from a sorted list
def removeDuplicates(head):
# Pointer to store the pointer of a node
# to be deleted to_free
# do nothing if the list is empty
if (head == None):
return
# Traverse the list till last node
if (head.next != None):
# Compare head node with next node
if (head.data == head.next.data):
# The sequence of steps is important.
# to_free pointer stores the next of head
# pointer which is to be deleted.
to_free = head.next
head.next = head.next.next
# free(to_free)
removeDuplicates(head)
# This is tricky: only advance if no deletion
else:
removeDuplicates(head.next)
return head
# UTILITY FUNCTIONS
# Function to insert a node at the
# beginning of the linked list
def push(head_ref, new_data):
# allocate node
new_node = Node(new_data)
# put in the data
new_node.data = new_data
# link the old list off the new node
new_node.next = head_ref
# move the head to point to the new node
head_ref = new_node
return head_ref
# Function to print nodes in a given linked list
def printList(node):
while (node != None):
print(node.data, end = " ")
node = node.next
# Driver code
if __name__=='__main__':
# Start with the empty list
head = None
# Let us create a sorted linked list
# to test the functions
# Created linked list will be 11.11.11.13.13.20
head = push(head, 20)
head = push(head, 13)
head = push(head, 13)
head = push(head, 11)
head = push(head, 11)
head = push(head, 11)
print("Linked list before duplicate removal ",
end = "")
printList(head)
# Remove duplicates from linked list
removeDuplicates(head)
print("\nLinked list after duplicate removal ",
end = "")
printList(head)
# This code is contributed by SrathoreC#
// C# Program to remove duplicates
// from a sorted linked list
using System;
class GFG
{
/* Link list node */
public class Node
{
public int data;
public Node next;
};
// The function removes duplicates
// from a sorted list
static Node removeDuplicates(Node head)
{
/* Pointer to store the pointer
of a node to be deleted*/
Node to_free;
/* do nothing if the list is empty */
if (head == null)
return null;
/* Traverse the list till last node */
if (head.next != null)
{
/* Compare head node with next node */
if (head.data == head.next.data)
{
/* The sequence of steps is important.
to_free pointer stores the next of head
pointer which is to be deleted.*/
to_free = head.next;
head.next = head.next.next;
removeDuplicates(head);
}
/* This is tricky: only advance if no deletion */
else
{
removeDuplicates(head.next);
}
}
return head;
}
/* UTILITY FUNCTIONS */
/* Function to insert a node at the beginning
of the linked list */
static Node push(Node head_ref,
int new_data)
{
/* allocate node */
Node new_node = new Node();
/* put in the data */
new_node.data = new_data;
/* link the old list off the new node */
new_node.next = (head_ref);
/* move the head to point to the new node */
(head_ref) = new_node;
return head_ref;
}
/* Function to print nodes in
a given linked list */
static void printList(Node node)
{
while (node != null)
{
Console.Write(" " + node.data);
node = node.next;
}
}
// Driver code
public static void Main(String []args)
{
/* Start with the empty list */
Node head = null;
/* Let us create a sorted linked list
to test the functions
Created linked list will be 11.11.11.13.13.20 */
head = push(head, 20);
head = push(head, 13);
head = push(head, 13);
head = push(head, 11);
head = push(head, 11);
head = push(head, 11);
Console.Write("Linked list before" +
" duplicate removal ");
printList(head);
/* Remove duplicates from linked list */
head = removeDuplicates(head);
Console.Write("\nLinked list after" +
" duplicate removal ");
printList(head);
}
}
// This code is contributed by PrinciRaj1992Javascript
C++14
// C++ program to remove duplicates
// from a sorted linked list
#include
using namespace std;
// Linked list Node
struct Node
{
int data;
Node *next;
Node(int d)
{
data = d;
next = NULL;
}
};
// Function to remove duplicates
// from the given linked list
Node *removeDuplicates(Node *head)
{
// Two references to head
// temp will iterate to the
// whole Linked List
// prev will point towards
// the first occurrence of every element
Node *temp = head,*prev=head;
// Traverse list till the last node
while (temp != NULL)
{
// Compare values of both pointers
if(temp->data != prev->data)
{
/* if the value of prev is
not equal to the value of
temp that means there are no
more occurrences of the prev data->
So we can set the next of
prev to the temp node->*/
prev->next = temp;
prev = temp;
}
/*Set the temp to the next node*/
temp = temp->next;
}
/*This is the edge case if there
are more than one occurrences
of the last element*/
if(prev != temp)
{
prev->next = NULL;
}
return head;
}
Node *push(Node *head, int new_data)
{
/* 1 & 2: Allocate the Node &
Put in the data*/
Node *new_node = new Node(new_data);
/* 3. Make next of new Node as head */
new_node->next = head;
/* 4. Move the head to point to new Node */
head = new_node;
return head;
}
/* Function to print linked list */
void printList(Node *head)
{
Node *temp = head;
while (temp != NULL)
{
cout << temp->data << " ";
temp = temp->next;
}
cout << endl;
}
/* Driver code */
int main()
{
Node *llist = NULL;
llist = push(llist,20);
llist = push(llist,13);
llist = push(llist,13);
llist = push(llist,11);
llist = push(llist,11);
llist = push(llist,11);
cout << ("List before removal of duplicates\n");
printList(llist);
cout << ("List after removal of elements\n");
llist = removeDuplicates(llist);
printList(llist);
}
// This code is contributed by mohit kumar 29. Java
// Java program to remove duplicates
// from a sorted linked list
class LinkedList
{
// head of list
Node head;
// Linked list Node
class Node
{
int data;
Node next;
Node(int d) {
data = d;
next = null;
}
}
// Function to remove duplicates
// from the given linked list
void removeDuplicates()
{
// Two references to head
// temp will iterate to the
// whole Linked List
// prev will point towards
// the first occurrence of every element
Node temp = head,prev=head;
// Traverse list till the last node
while (temp != null) {
// Compare values of both pointers
if(temp.data!=prev.data)
{
/* if the value of prev is
not equal to the value of
temp that means there are no
more occurrences of the prev data.
So we can set the next of
prev to the temp node.*/
prev.next=temp;
prev=temp;
}
/*Set the temp to the next node*/
temp=temp.next;
}
/*This is the edge case if there
are more than one occurrences
of the last element*/
if(prev!=temp){
prev.next=null;
}
}
/* Utility functions */
/* Inserts a new Node at front of the list. */
public void push(int new_data)
{
/* 1 & 2: Allocate the Node &
Put in the data*/
Node new_node = new Node(new_data);
/* 3. Make next of new Node as head */
new_node.next = head;
/* 4. Move the head to point to new Node */
head = new_node;
}
/* Function to print linked list */
void printList()
{
Node temp = head;
while (temp != null)
{
System.out.print(temp.data+" ");
temp = temp.next;
}
System.out.println();
}
/* Driver program to test above functions */
public static void main(String args[])
{
LinkedList llist = new LinkedList();
llist.push(20);
llist.push(13);
llist.push(13);
llist.push(11);
llist.push(11);
llist.push(11);
System.out.print("List before ");
System.out.println("removal of duplicates");
llist.printList();
llist.removeDuplicates();
System.out.println("List after removal of elements");
llist.printList();
}
}
/* This code is contributed by Arshita */Python3
# Python3 program to remove duplicates
# from a sorted linked list
import math
# Link list node
class Node:
def __init__(self, data):
self.data = data
self.next = None
# The function removes duplicates
# from the given linked list
def removeDuplicates(head):
# Do nothing if the list consist of
# only one element or empty
if (head == None and
head.next == None):
return
# Consturct a pointer
# pointing towards head
current = head
# Initialise a while loop till the
# second last node of the linkedlist
while (current.next):
# If the data of current and next
# node is equal we will skip the
# node between them
if current.data == current.next.data:
current.next = current.next.next
# If the data of current and
# next node is different move
# the pointer to the next node
else:
current = current.next
return
# UTILITY FUNCTIONS
# Function to insert a node at the
# beginning of the linked list
def push(head_ref, new_data):
# Allocate node
new_node = Node(new_data)
# Put in the data
new_node.data = new_data
# Link the old list off
# the new node
new_node.next = head_ref
# Move the head to point
# to the new node
head_ref = new_node
return head_ref
# Function to print nodes
# in a given linked list
def printList(node):
while (node != None):
print(node.data, end = " ")
node = node.next
# Driver code
if __name__=='__main__':
head = None
head = push(head, 20)
head = push(head, 13)
head = push(head, 13)
head = push(head, 11)
head = push(head, 11)
head = push(head, 11)
print("List before removal of "
"duplicates ", end = "")
printList(head)
removeDuplicates(head)
print("\nList after removal of "
"elements ", end = "")
printList(head)
# This code is contributed by MukulTomarC#
// C# program to remove duplicates
// from a sorted linked list
using System;
class LinkedList
{
// head of list
public Node head;
// Linked list Node
public class Node
{
public int data;
public Node next;
public Node(int d) {
data = d;
next = null;
}
}
// Function to remove duplicates
// from the given linked list
void removeDuplicates()
{
// Two references to head
// temp will iterate to the
// whole Linked List
// prev will point towards
// the first occurrence of every element
Node temp = head, prev = head;
// Traverse list till the last node
while (temp != null) {
// Compare values of both pointers
if(temp.data != prev.data)
{
/* if the value of prev is
not equal to the value of
temp that means there are no
more occurrences of the prev data.
So we can set the next of
prev to the temp node.*/
prev.next = temp;
prev = temp;
}
/*Set the temp to the next node*/
temp = temp.next;
}
/*This is the edge case if there
are more than one occurrences
of the last element*/
if(prev != temp){
prev.next = null;
}
}
/* Utility functions */
/* Inserts a new Node at front of the list. */
public void push(int new_data)
{
/* 1 & 2: Allocate the Node &
Put in the data*/
Node new_node = new Node(new_data);
/* 3. Make next of new Node as head */
new_node.next = head;
/* 4. Move the head to point to new Node */
head = new_node;
}
/* Function to print linked list */
void printList()
{
Node temp = head;
while (temp != null)
{
Console.Write(temp.data + " ");
temp = temp.next;
}
Console.WriteLine();
}
/* Driver code */
public static void Main(string []args)
{
LinkedList llist = new LinkedList();
llist.push(20);
llist.push(13);
llist.push(13);
llist.push(11);
llist.push(11);
llist.push(11);
Console.Write("List before ");
Console.WriteLine("removal of duplicates");
llist.printList();
llist.removeDuplicates();
Console.WriteLine("List after removal of elements");
llist.printList();
}
}
// This code is contributed by rutvik_56Javascript
C++
// CPP program for the above approach
#include
using namespace std;
/* Link list node */
struct Node {
int data;
Node* next;
Node()
{
data = 0;
next = NULL;
}
};
/* Function to insert a node at
the beginning of the linked
* list */
void push(Node** head_ref, int new_data)
{
/* allocate node */
Node* new_node = new Node();
/* put in the data */
new_node->data = new_data;
/* link the old list off
the new node */
new_node->next = (*head_ref);
/* move the head to point
to the new node */
(*head_ref) = new_node;
}
/* Function to print nodes
in a given linked list */
void printList(Node* node)
{
while (node != NULL) {
cout << node->data << " ";
node = node->next;
}
}
// Function to remove duplicates
void removeDuplicates(Node* head)
{
unordered_map track;
Node* temp = head;
while (temp) {
if (track.find(temp->data) == track.end()) {
cout << temp->data << " ";
}
track[temp->data] = true;
temp = temp->next;
}
}
// Driver Code
int main()
{
Node* head = NULL;
/* Created linked list will be
11->11->11->13->13->20 */
push(&head, 20);
push(&head, 13);
push(&head, 13);
push(&head, 11);
push(&head, 11);
push(&head, 11);
cout << "Linked list before duplicate removal ";
printList(head);
cout << "\nLinked list after duplicate removal ";
removeDuplicates(head);
return 0;
}
// This code is contributed by yashbeersingh42 Java
// Java program for the above approach
import java.io.*;
import java.util.*;
class Node
{
int data;
Node next;
Node()
{
data = 0;
next = null;
}
}
class GFG
{
/* Function to insert a node at
the beginning of the linked
* list */
static Node push(Node head_ref, int new_data)
{
/* allocate node */
Node new_node = new Node();
/* put in the data */
new_node.data = new_data;
/* link the old list off
the new node */
new_node.next = (head_ref);
/* move the head to point
to the new node */
head_ref = new_node;
return head_ref;
}
/* Function to print nodes
in a given linked list */
static void printList(Node node)
{
while (node != null)
{
System.out.print(node.data + " ");
node = node.next;
}
}
// Function to remove duplicates
static void removeDuplicates(Node head)
{
HashMap track = new HashMap<>();
Node temp = head;
while(temp != null)
{
if(!track.containsKey(temp.data))
{
System.out.print(temp.data + " ");
}
track.put(temp.data , true);
temp = temp.next;
}
}
// Driver Code
public static void main (String[] args)
{
Node head = null;
/* Created linked list will be
11->11->11->13->13->20 */
head = push(head, 20);
head = push(head, 13);
head = push(head, 13);
head = push(head, 11);
head = push(head, 11);
head = push(head, 11);
System.out.print("Linked list before duplicate removal ");
printList(head);
System.out.print("\nLinked list after duplicate removal ");
removeDuplicates(head);
}
}
// This code is contributed by avanitrachhadiya2155 C#
// C# program for the above approach
using System;
using System.Collections.Generic;
public class Node
{
public int data;
public Node next;
public Node()
{
data = 0;
next = null;
}
}
public class GFG
{
/* Function to insert a node at
the beginning of the linked
* list */
static Node push(Node head_ref, int new_data)
{
/* allocate node */
Node new_node = new Node();
/* put in the data */
new_node.data = new_data;
/* link the old list off
the new node */
new_node.next = (head_ref);
/* move the head to point
to the new node */
head_ref = new_node;
return head_ref;
}
/* Function to print nodes
in a given linked list */
static void printList(Node node)
{
while (node != null)
{
Console.Write(node.data + " ");
node = node.next;
}
}
// Function to remove duplicates
static void removeDuplicates(Node head)
{
Dictionary track = new Dictionary();
Node temp = head;
while(temp != null)
{
if(!track.ContainsKey(temp.data))
{
Console.Write(temp.data + " ");
track.Add(temp.data , true);
}
temp = temp.next;
}
}
// Driver Code
static public void Main ()
{
Node head = null;
/* Created linked list will be
11->11->11->13->13->20 */
head = push(head, 20);
head = push(head, 13);
head = push(head, 13);
head = push(head, 11);
head = push(head, 11);
head = push(head, 11);
Console.Write("Linked list before duplicate removal ");
printList(head);
Console.Write("\nLinked list after duplicate removal ");
removeDuplicates(head);
}
}
// This code is contributed by rag2127 Javascript
输出
Linked list before duplicate removal 11 11 11 13 13 20
Linked list after duplicate removal 11 13 20时间复杂度： O(n)，其中 n 是给定链表中的节点数。
递归方法：
C++
/* C++ Program to remove duplicates
from a sorted linked list */
#include
using namespace std;
/* Link list node */
class Node
{
public:
int data;
Node* next;
};
/* The function removes duplicates
from a sorted list */
void removeDuplicates(Node* head)
{
/* Pointer to store the pointer of a node to be deleted*/
Node* to_free;
/* do nothing if the list is empty */
if (head == NULL)
return;
/* Traverse the list till last node */
if (head->next != NULL)
{
/* Compare head node with next node */
if (head->data == head->next->data)
{
/* The sequence of steps is important.
to_free pointer stores the next of head
pointer which is to be deleted.*/
to_free = head->next;
head->next = head->next->next;
free(to_free);
removeDuplicates(head);
}
else /* This is tricky: only
advance if no deletion */
{
removeDuplicates(head->next);
}
}
}
/* UTILITY FUNCTIONS */
/* Function to insert a node at the
beginning of the linked list */
void push(Node** head_ref, int new_data)
{
/* allocate node */
Node* new_node = new Node();
/* put in the data */
new_node->data = new_data;
/* link the old list off the new node */
new_node->next = (*head_ref);
/* move the head to point to the new node */
(*head_ref) = new_node;
}
/* Function to print nodes
in a given linked list */
void printList(Node *node)
{
while (node!=NULL)
{
cout<<" "<data;
node = node->next;
}
}
/* Driver code*/
int main()
{
/* Start with the empty list */
Node* head = NULL;
/* Let us create a sorted linked
list to test the functions
Created linked list will be
11->11->11->13->13->20 */
push(&head, 20);
push(&head, 13);
push(&head, 13);
push(&head, 11);
push(&head, 11);
push(&head, 11);
cout<<"Linked list before duplicate removal ";
printList(head);
/* Remove duplicates from linked list */
removeDuplicates(head);
cout<<"\nLinked list after duplicate removal ";
printList(head);
return 0;
}
// This code is contributed by Ashita Gupta
C
/* C recursive Program to remove duplicates from a sorted linked list */
#include
#include
/* Link list node */
struct Node
{
int data;
struct Node* next;
};
/* UTILITY FUNCTIONS */
/* Function to insert a node at the beginning of the linked list */
void push(struct Node** head_ref, int new_data)
{
/* allocate node */
struct Node* new_node =
(struct Node*) malloc(sizeof(struct Node));
/* put in the data */
new_node->data = new_data;
/* link the old list off the new node */
new_node->next = (*head_ref);
/* move the head to point to the new node */
(*head_ref) = new_node;
}
/* Function to print nodes in a given linked list */
void printList(struct Node *node)
{
while (node!=NULL)
{
printf("%d ", node->data);
node = node->next;
}
}
Node* deleteDuplicates(Node* head) {
if (head == nullptr) return nullptr;
if (head->next == nullptr) return head;
if (head->data == head->next->data) {
Node *tmp;
// If find next element duplicate, preserve the next pointer to be deleted,
// skip it, and then delete the stored one. Return head
tmp = head->next;
head->next = head->next->next;
free(tmp);
return deleteDuplicates(head);
}
else {
// if doesn't find next element duplicate, leave head
// and check from next element
head->next = deleteDuplicates(head->next);
return head;
}
}
int main()
{
/* Start with the empty list */
struct Node* head = NULL;
/* Let us create a sorted linked list to test the functions
Created linked list will be 11->11->11->13->13->20 */
push(&head, 20);
push(&head, 13);
push(&head, 13);
push(&head, 11);
push(&head, 11);
push(&head, 11);
printf("\n Linked list before duplicate removal ");
printList(head);
/* Remove duplicates from linked list */
head = deleteDuplicates(head);
printf("\n Linked list after duplicate removal ");
printList(head);
return 0;
}
/* This code is contributed by Yogesh shukla */
Java
// Java Program to remove duplicates
// from a sorted linked list
class GFG
{
/* Link list node */
static class Node
{
int data;
Node next;
};
// The function removes duplicates
// from a sorted list
static Node removeDuplicates(Node head)
{
/* Pointer to store the pointer
of a node to be deleted*/
Node to_free;
/* do nothing if the list is empty */
if (head == null)
return null;
/* Traverse the list till last node */
if (head.next != null)
{
/* Compare head node with next node */
if (head.data == head.next.data)
{
/* The sequence of steps is important.
to_free pointer stores the next of head
pointer which is to be deleted.*/
to_free = head.next;
head.next = head.next.next;
removeDuplicates(head);
}
/* This is tricky: only advance if no deletion */
else
{
removeDuplicates(head.next);
}
}
return head;
}
/* UTILITY FUNCTIONS */
/* Function to insert a node at the beginning
of the linked list */
static Node push(Node head_ref,
int new_data)
{
/* allocate node */
Node new_node = new Node();
/* put in the data */
new_node.data = new_data;
/* link the old list off the new node */
new_node.next = (head_ref);
/* move the head to point to the new node */
(head_ref) = new_node;
return head_ref;
}
/* Function to print nodes in a given linked list */
static void printList(Node node)
{
while (node != null)
{
System.out.print(" " + node.data);
node = node.next;
}
}
/* Driver code*/
public static void main(String args[])
{
/* Start with the empty list */
Node head = null;
/* Let us create a sorted linked list
to test the functions
Created linked list will be 11.11.11.13.13.20 */
head = push(head, 20);
head = push(head, 13);
head = push(head, 13);
head = push(head, 11);
head = push(head, 11);
head = push(head, 11);
System.out.println("Linked list before" +
" duplicate removal ");
printList(head);
/* Remove duplicates from linked list */
head = removeDuplicates(head);
System.out.println("\nLinked list after" +
" duplicate removal ");
printList(head);
}
}
// This code is contributed by Arnab Kundu
蟒蛇3
# Python3 Program to remove duplicates
# from a sorted linked list
import math
# Link list node
class Node:
def __init__(self,data):
self.data = data
self.next = None
# The function removes duplicates
# from a sorted list
def removeDuplicates(head):
# Pointer to store the pointer of a node
# to be deleted to_free
# do nothing if the list is empty
if (head == None):
return
# Traverse the list till last node
if (head.next != None):
# Compare head node with next node
if (head.data == head.next.data):
# The sequence of steps is important.
# to_free pointer stores the next of head
# pointer which is to be deleted.
to_free = head.next
head.next = head.next.next
# free(to_free)
removeDuplicates(head)
# This is tricky: only advance if no deletion
else:
removeDuplicates(head.next)
return head
# UTILITY FUNCTIONS
# Function to insert a node at the
# beginning of the linked list
def push(head_ref, new_data):
# allocate node
new_node = Node(new_data)
# put in the data
new_node.data = new_data
# link the old list off the new node
new_node.next = head_ref
# move the head to point to the new node
head_ref = new_node
return head_ref
# Function to print nodes in a given linked list
def printList(node):
while (node != None):
print(node.data, end = " ")
node = node.next
# Driver code
if __name__=='__main__':
# Start with the empty list
head = None
# Let us create a sorted linked list
# to test the functions
# Created linked list will be 11.11.11.13.13.20
head = push(head, 20)
head = push(head, 13)
head = push(head, 13)
head = push(head, 11)
head = push(head, 11)
head = push(head, 11)
print("Linked list before duplicate removal ",
end = "")
printList(head)
# Remove duplicates from linked list
removeDuplicates(head)
print("\nLinked list after duplicate removal ",
end = "")
printList(head)
# This code is contributed by Srathore
C＃
// C# Program to remove duplicates
// from a sorted linked list
using System;
class GFG
{
/* Link list node */
public class Node
{
public int data;
public Node next;
};
// The function removes duplicates
// from a sorted list
static Node removeDuplicates(Node head)
{
/* Pointer to store the pointer
of a node to be deleted*/
Node to_free;
/* do nothing if the list is empty */
if (head == null)
return null;
/* Traverse the list till last node */
if (head.next != null)
{
/* Compare head node with next node */
if (head.data == head.next.data)
{
/* The sequence of steps is important.
to_free pointer stores the next of head
pointer which is to be deleted.*/
to_free = head.next;
head.next = head.next.next;
removeDuplicates(head);
}
/* This is tricky: only advance if no deletion */
else
{
removeDuplicates(head.next);
}
}
return head;
}
/* UTILITY FUNCTIONS */
/* Function to insert a node at the beginning
of the linked list */
static Node push(Node head_ref,
int new_data)
{
/* allocate node */
Node new_node = new Node();
/* put in the data */
new_node.data = new_data;
/* link the old list off the new node */
new_node.next = (head_ref);
/* move the head to point to the new node */
(head_ref) = new_node;
return head_ref;
}
/* Function to print nodes in
a given linked list */
static void printList(Node node)
{
while (node != null)
{
Console.Write(" " + node.data);
node = node.next;
}
}
// Driver code
public static void Main(String []args)
{
/* Start with the empty list */
Node head = null;
/* Let us create a sorted linked list
to test the functions
Created linked list will be 11.11.11.13.13.20 */
head = push(head, 20);
head = push(head, 13);
head = push(head, 13);
head = push(head, 11);
head = push(head, 11);
head = push(head, 11);
Console.Write("Linked list before" +
" duplicate removal ");
printList(head);
/* Remove duplicates from linked list */
head = removeDuplicates(head);
Console.Write("\nLinked list after" +
" duplicate removal ");
printList(head);
}
}
// This code is contributed by PrinciRaj1992
Javascript
输出
Linked list before duplicate removal 11 11 11 13 13 20
Linked list after duplicate removal 11 13 20另一种方法：创建一个指针指向每个元素的第一次出现，另一个指针 temp 将迭代到每个元素，当前一个指针的值不等于临时指针时，我们将设置前一个指针的指针指向第一次出现的另一个节点的指针。
下面是上述方法的实现：
C++14
// C++ program to remove duplicates
// from a sorted linked list
#include
using namespace std;
// Linked list Node
struct Node
{
int data;
Node *next;
Node(int d)
{
data = d;
next = NULL;
}
};
// Function to remove duplicates
// from the given linked list
Node *removeDuplicates(Node *head)
{
// Two references to head
// temp will iterate to the
// whole Linked List
// prev will point towards
// the first occurrence of every element
Node *temp = head,*prev=head;
// Traverse list till the last node
while (temp != NULL)
{
// Compare values of both pointers
if(temp->data != prev->data)
{
/* if the value of prev is
not equal to the value of
temp that means there are no
more occurrences of the prev data->
So we can set the next of
prev to the temp node->*/
prev->next = temp;
prev = temp;
}
/*Set the temp to the next node*/
temp = temp->next;
}
/*This is the edge case if there
are more than one occurrences
of the last element*/
if(prev != temp)
{
prev->next = NULL;
}
return head;
}
Node *push(Node *head, int new_data)
{
/* 1 & 2: Allocate the Node &
Put in the data*/
Node *new_node = new Node(new_data);
/* 3. Make next of new Node as head */
new_node->next = head;
/* 4. Move the head to point to new Node */
head = new_node;
return head;
}
/* Function to print linked list */
void printList(Node *head)
{
Node *temp = head;
while (temp != NULL)
{
cout << temp->data << " ";
temp = temp->next;
}
cout << endl;
}
/* Driver code */
int main()
{
Node *llist = NULL;
llist = push(llist,20);
llist = push(llist,13);
llist = push(llist,13);
llist = push(llist,11);
llist = push(llist,11);
llist = push(llist,11);
cout << ("List before removal of duplicates\n");
printList(llist);
cout << ("List after removal of elements\n");
llist = removeDuplicates(llist);
printList(llist);
}
// This code is contributed by mohit kumar 29.
Java
// Java program to remove duplicates
// from a sorted linked list
class LinkedList
{
// head of list
Node head;
// Linked list Node
class Node
{
int data;
Node next;
Node(int d) {
data = d;
next = null;
}
}
// Function to remove duplicates
// from the given linked list
void removeDuplicates()
{
// Two references to head
// temp will iterate to the
// whole Linked List
// prev will point towards
// the first occurrence of every element
Node temp = head,prev=head;
// Traverse list till the last node
while (temp != null) {
// Compare values of both pointers
if(temp.data!=prev.data)
{
/* if the value of prev is
not equal to the value of
temp that means there are no
more occurrences of the prev data.
So we can set the next of
prev to the temp node.*/
prev.next=temp;
prev=temp;
}
/*Set the temp to the next node*/
temp=temp.next;
}
/*This is the edge case if there
are more than one occurrences
of the last element*/
if(prev!=temp){
prev.next=null;
}
}
/* Utility functions */
/* Inserts a new Node at front of the list. */
public void push(int new_data)
{
/* 1 & 2: Allocate the Node &
Put in the data*/
Node new_node = new Node(new_data);
/* 3. Make next of new Node as head */
new_node.next = head;
/* 4. Move the head to point to new Node */
head = new_node;
}
/* Function to print linked list */
void printList()
{
Node temp = head;
while (temp != null)
{
System.out.print(temp.data+" ");
temp = temp.next;
}
System.out.println();
}
/* Driver program to test above functions */
public static void main(String args[])
{
LinkedList llist = new LinkedList();
llist.push(20);
llist.push(13);
llist.push(13);
llist.push(11);
llist.push(11);
llist.push(11);
System.out.print("List before ");
System.out.println("removal of duplicates");
llist.printList();
llist.removeDuplicates();
System.out.println("List after removal of elements");
llist.printList();
}
}
/* This code is contributed by Arshita */
蟒蛇3
# Python3 program to remove duplicates
# from a sorted linked list
import math
# Link list node
class Node:
def __init__(self, data):
self.data = data
self.next = None
# The function removes duplicates
# from the given linked list
def removeDuplicates(head):
# Do nothing if the list consist of
# only one element or empty
if (head == None and
head.next == None):
return
# Consturct a pointer
# pointing towards head
current = head
# Initialise a while loop till the
# second last node of the linkedlist
while (current.next):
# If the data of current and next
# node is equal we will skip the
# node between them
if current.data == current.next.data:
current.next = current.next.next
# If the data of current and
# next node is different move
# the pointer to the next node
else:
current = current.next
return
# UTILITY FUNCTIONS
# Function to insert a node at the
# beginning of the linked list
def push(head_ref, new_data):
# Allocate node
new_node = Node(new_data)
# Put in the data
new_node.data = new_data
# Link the old list off
# the new node
new_node.next = head_ref
# Move the head to point
# to the new node
head_ref = new_node
return head_ref
# Function to print nodes
# in a given linked list
def printList(node):
while (node != None):
print(node.data, end = " ")
node = node.next
# Driver code
if __name__=='__main__':
head = None
head = push(head, 20)
head = push(head, 13)
head = push(head, 13)
head = push(head, 11)
head = push(head, 11)
head = push(head, 11)
print("List before removal of "
"duplicates ", end = "")
printList(head)
removeDuplicates(head)
print("\nList after removal of "
"elements ", end = "")
printList(head)
# This code is contributed by MukulTomar
C＃
// C# program to remove duplicates
// from a sorted linked list
using System;
class LinkedList
{
// head of list
public Node head;
// Linked list Node
public class Node
{
public int data;
public Node next;
public Node(int d) {
data = d;
next = null;
}
}
// Function to remove duplicates
// from the given linked list
void removeDuplicates()
{
// Two references to head
// temp will iterate to the
// whole Linked List
// prev will point towards
// the first occurrence of every element
Node temp = head, prev = head;
// Traverse list till the last node
while (temp != null) {
// Compare values of both pointers
if(temp.data != prev.data)
{
/* if the value of prev is
not equal to the value of
temp that means there are no
more occurrences of the prev data.
So we can set the next of
prev to the temp node.*/
prev.next = temp;
prev = temp;
}
/*Set the temp to the next node*/
temp = temp.next;
}
/*This is the edge case if there
are more than one occurrences
of the last element*/
if(prev != temp){
prev.next = null;
}
}
/* Utility functions */
/* Inserts a new Node at front of the list. */
public void push(int new_data)
{
/* 1 & 2: Allocate the Node &
Put in the data*/
Node new_node = new Node(new_data);
/* 3. Make next of new Node as head */
new_node.next = head;
/* 4. Move the head to point to new Node */
head = new_node;
}
/* Function to print linked list */
void printList()
{
Node temp = head;
while (temp != null)
{
Console.Write(temp.data + " ");
temp = temp.next;
}
Console.WriteLine();
}
/* Driver code */
public static void Main(string []args)
{
LinkedList llist = new LinkedList();
llist.push(20);
llist.push(13);
llist.push(13);
llist.push(11);
llist.push(11);
llist.push(11);
Console.Write("List before ");
Console.WriteLine("removal of duplicates");
llist.printList();
llist.removeDuplicates();
Console.WriteLine("List after removal of elements");
llist.printList();
}
}
// This code is contributed by rutvik_56
Javascript
输出
List before removal of duplicates
11 11 11 13 13 20
List after removal of elements
11 13 20 另一种方法：使用地图
这个想法是推送地图中的所有值并打印其键。
下面是上述方法的实现：
C++
// CPP program for the above approach
#include
using namespace std;
/* Link list node */
struct Node {
int data;
Node* next;
Node()
{
data = 0;
next = NULL;
}
};
/* Function to insert a node at
the beginning of the linked
* list */
void push(Node** head_ref, int new_data)
{
/* allocate node */
Node* new_node = new Node();
/* put in the data */
new_node->data = new_data;
/* link the old list off
the new node */
new_node->next = (*head_ref);
/* move the head to point
to the new node */
(*head_ref) = new_node;
}
/* Function to print nodes
in a given linked list */
void printList(Node* node)
{
while (node != NULL) {
cout << node->data << " ";
node = node->next;
}
}
// Function to remove duplicates
void removeDuplicates(Node* head)
{
unordered_map track;
Node* temp = head;
while (temp) {
if (track.find(temp->data) == track.end()) {
cout << temp->data << " ";
}
track[temp->data] = true;
temp = temp->next;
}
}
// Driver Code
int main()
{
Node* head = NULL;
/* Created linked list will be
11->11->11->13->13->20 */
push(&head, 20);
push(&head, 13);
push(&head, 13);
push(&head, 11);
push(&head, 11);
push(&head, 11);
cout << "Linked list before duplicate removal ";
printList(head);
cout << "\nLinked list after duplicate removal ";
removeDuplicates(head);
return 0;
}
// This code is contributed by yashbeersingh42
Java
// Java program for the above approach
import java.io.*;
import java.util.*;
class Node
{
int data;
Node next;
Node()
{
data = 0;
next = null;
}
}
class GFG
{
/* Function to insert a node at
the beginning of the linked
* list */
static Node push(Node head_ref, int new_data)
{
/* allocate node */
Node new_node = new Node();
/* put in the data */
new_node.data = new_data;
/* link the old list off
the new node */
new_node.next = (head_ref);
/* move the head to point
to the new node */
head_ref = new_node;
return head_ref;
}
/* Function to print nodes
in a given linked list */
static void printList(Node node)
{
while (node != null)
{
System.out.print(node.data + " ");
node = node.next;
}
}
// Function to remove duplicates
static void removeDuplicates(Node head)
{
HashMap track = new HashMap<>();
Node temp = head;
while(temp != null)
{
if(!track.containsKey(temp.data))
{
System.out.print(temp.data + " ");
}
track.put(temp.data , true);
temp = temp.next;
}
}
// Driver Code
public static void main (String[] args)
{
Node head = null;
/* Created linked list will be
11->11->11->13->13->20 */
head = push(head, 20);
head = push(head, 13);
head = push(head, 13);
head = push(head, 11);
head = push(head, 11);
head = push(head, 11);
System.out.print("Linked list before duplicate removal ");
printList(head);
System.out.print("\nLinked list after duplicate removal ");
removeDuplicates(head);
}
}
// This code is contributed by avanitrachhadiya2155
C＃
// C# program for the above approach
using System;
using System.Collections.Generic;
public class Node
{
public int data;
public Node next;
public Node()
{
data = 0;
next = null;
}
}
public class GFG
{
/* Function to insert a node at
the beginning of the linked
* list */
static Node push(Node head_ref, int new_data)
{
/* allocate node */
Node new_node = new Node();
/* put in the data */
new_node.data = new_data;
/* link the old list off
the new node */
new_node.next = (head_ref);
/* move the head to point
to the new node */
head_ref = new_node;
return head_ref;
}
/* Function to print nodes
in a given linked list */
static void printList(Node node)
{
while (node != null)
{
Console.Write(node.data + " ");
node = node.next;
}
}
// Function to remove duplicates
static void removeDuplicates(Node head)
{
Dictionary track = new Dictionary();
Node temp = head;
while(temp != null)
{
if(!track.ContainsKey(temp.data))
{
Console.Write(temp.data + " ");
track.Add(temp.data , true);
}
temp = temp.next;
}
}
// Driver Code
static public void Main ()
{
Node head = null;
/* Created linked list will be
11->11->11->13->13->20 */
head = push(head, 20);
head = push(head, 13);
head = push(head, 13);
head = push(head, 11);
head = push(head, 11);
head = push(head, 11);
Console.Write("Linked list before duplicate removal ");
printList(head);
Console.Write("\nLinked list after duplicate removal ");
removeDuplicates(head);
}
}
// This code is contributed by rag2127
Javascript
输出
Linked list before duplicate removal 11 11 11 13 13 20
Linked list after duplicate removal 11 13 20 时间复杂度： O（节点数）
空间复杂度： O（节点数）
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