📜  数据结构示例-删除循环链表中重复的元素

📅  最后修改于: 2020-10-15 06:22:31             🧑  作者: Mango

问:程序从循环链表中删除重复的元素。

说明

在此程序中,我们将创建一个循环链接列表,并从列表中删除重复的节点。我们将把一个节点与列表的其余部分进行比较,并检查是否重复。如果找到重复节点,请从列表中删除重复节点。

1-> 2-> 2-> 4-> 3

在上面的列表中,我们可以看到,节点2在列表中存在两次。因此,我们将有一个节点电流将遍历列表。索引将指向当前的下一个节点。 Temp将指向索引之前的节点。找到重复项后,我们将temp.next指向index.next来删除它。删除重复项后的上述列表:

1-> 2-> 4-> 3

算法

  • 定义一个Node类,该类代表列表中的一个节点。它具有两个属性数据,下一个将指向下一个节点。
  • 定义另一个用于创建循环链接列表的类,它具有两个节点:head和tail。
  • removeDuplicate()将从列表中删除重复的节点:
    1. 节点当前将指向头部,并用于遍历列表。
    2. 索引将指向当前节点的下一个节点,而温度将指向索引的前一个节点。
    3. 我们将把current.data与index.data进行比较。如果找到匹配项,则通过将temp指向索引的next来删除重复的数据。
    4. 将index递增到index.next,将current递增到current .next。
    5. 从c到d重复步骤,直到所有重复项都被删除。

示例:

Python

#Represents the node of list.
#Represents the node of list.
class Node:
  def __init__(self,data):
    self.data = data;
    self.next = None;

class CreateList:
  #Declaring head and tail pointer as null.
  def __init__(self):
    self.head = Node(None);
    self.tail = Node(None);
    self.head.next = self.tail;
    self.tail.next = self.head;
  
  #This function will add the new node at the end of the list.
  def add(self,data):
    newNode = Node(data);
    #Checks if the list is empty.
    if self.head.data is None:
      #If list is empty, both head and tail would point to new node.
      self.head = newNode;
      self.tail = newNode;
      newNode.next = self.head;
    else:
      #tail will point to new node.
      self.tail.next = newNode;
      #New node will become new tail.
      self.tail = newNode;
      #Since, it is circular linked list tail will point to head.
      self.tail.next = self.head;
  
  #Removes duplicate from the list
  def removeDuplicate(self):
    #Current will point to head
    current = self.head;
    if(self.head == None):
      print("List is empty");
    else:
      while(True):
        #Temp will point to previous node of index.
        temp = current;
        #Index will point to node next to current
        index = current.next;
        while(index != self.head):
          #If current node is equal to index data
          if(current.data == index.data):
            #Here, index node is pointing to the node which is duplicate of current node
            #Skips the duplicate node by pointing to next node
            temp.next = index.next;
          else:
            #Temp will point to previous node of index.
            temp = index;
          index= index.next;
        current =current.next;
        if(current.next == self.head):
          break;
          
  #Displays all the nodes in the list
  def display(self):
    current = self.head;
    if self.head is None:
      print("List is empty");
      return;
    else:
      #Prints each node by incrementing pointer.
      print(current.data);
      while(current.next != self.head):
        current = current.next;
        print(current.data);
    print("\n");
      
class CircularLinkedList:
  cl = CreateList();
  #Adds data to the list
  cl.add(1);
  cl.add(2);
  cl.add(3);
  cl.add(2);
  cl.add(2);
  cl.add(4);
  
  print("Originals list: ");
  cl.display();
  #Removes duplicate nodes
  cl.removeDuplicate();
  print("List after removing duplicates: ");
  cl.display();

输出:

Originals list: 
 1 2 3 2 2 4
List after removing duplicates: 
 1 2 3 4

C

#include 
#include 
#include 

//Represents the node of list.
struct node{
    int data;
    struct node *next;
};

//Declaring head and tail pointer as null.
struct node *head = NULL;
struct node *tail = NULL;

//This function will add the new node at the end of the list.
void add(int data){
    //Create new node
    struct node *newNode = (struct node*)malloc(sizeof(struct node));
    newNode->data = data;
    //Checks if the list is empty.
    if(head == NULL){
        //If list is empty, both head and tail would point to new node.
        head = newNode;
        tail = newNode;
        newNode->next = head;
    }else {
        //tail will point to new node.
tail->next = newNode;
//New node will become new tail.
tail = newNode;
//Since, it is circular linked list tail will point to head.
tail->next = head;
}
}

//Removes duplicate from the list
void removeDuplicate() {
//Current will point to head
struct node *current = head, *index = NULL, *temp = NULL;
if(head == NULL) {
printf("List is empty");
}
else {
do{
//Temp will point to previous node of index.
temp = current;
//Index will point to node next to current
index = current->next;
while(index != head) {
//If current node is equal to index data
if(current->data == index->data) {
//Here, index node is pointing to the node which is duplicate of current node
//Skips the duplicate node by pointing to next node
temp->next = index->next;
}
else{
     //Temp will point to previous node of index.
     temp = index;
}
index= index->next;
}
current =current->next;
}while(current->next != head); 
}
}
//This function will display the nodes of circular linked list
void display(){
    struct node *current = head;
    if(head == NULL){
        printf("List is empty");
    }
    else{
 do{
     //Prints each node by incrementing pointer.
printf("%d ", current->data);
current = current->next;
}while(current != head);
printf("\n");
    }
}
    
int main()
{
   //Adds data to the list
   add(1);
   add(2);
   add(3);
   add(2);
   add(2);
   add(4);
   printf("Originals list: \n");
   display();
   //Removes duplicate nodes
   removeDuplicate();
   printf("List after removing duplicates: \n");
   display();
   
   return 0;
}

输出:

Originals list: 
 1 2 3 2 2 4
List after removing duplicates: 
 1 2 3 4

JAVA

public class RemoveDuplicate {
//Represents the node of list.
public class Node{
int data;
Node next;
public Node(int data) {
this.data = data;
}
}
//Declaring head and tail pointer as null.
public Node head = null;
public Node tail = null;
//This function will add the new node at the end of the list.
public void add(int data){
//Create new node
Node newNode = new Node(data);
//Checks if the list is empty.
if(head == null) {
 //If list is empty, both head and tail would point to new node.
head = newNode;
tail = newNode;
newNode.next = head;
}
else {
//tail will point to new node.
tail.next = newNode;
//New node will become new tail.
tail = newNode;
//Since, it is circular linked list tail will points to head.
tail.next = head;
}
}
//Removes duplicate from the list
public void removeDuplicate() {
//Current will point to head
Node current = head, index = null, temp = null;
if(head == null) {
System.out.println("List is empty");
}
else {
do{
//Temp will point to previous node of index.
temp = current;
//Index will point to node next to current
index = current.next;
while(index != head) {
//If current node is equal to index data
if(current.data == index.data) {
//Here, index node is pointing to the node which is duplicate of current node
//Skips the duplicate node by pointing to next node
temp.next = index.next;
}
else {
//Temp will point to previous node of index.
temp = index;
}
index= index.next;
}
current =current.next;
}while(current.next != head); 
}
}
//Displays all the nodes in the list
public void display() {
Node current = head;
if(head == null) {
System.out.println("List is empty");
}
else {
 do{
//Prints each node by incrementing pointer.
System.out.print(" "+ current.data);
current = current.next;
}while(current != head);
System.out.println();
}
}
public static void main(String[] args) {
RemoveDuplicate cl = new RemoveDuplicate();
//Adds data to the list
cl.add(1);
cl.add(2);
cl.add(3);
cl.add(2);
cl.add(2);
cl.add(4);
System.out.println("Originals list: ");
cl.display();
//Removes duplicate nodes
cl.removeDuplicate();
System.out.println("List after removing duplicates: ");
cl.display();
}
}

输出:

Originals list: 
 1 2 3 2 2 4
List after removing duplicates: 
 1 2 3 4

C#

using System;
namespace CircularLinkedList
{
public class Program
{
//Represents the node of list.
public class Node{
public T data;
public Node next;
public Node(T value) {
data = value;
next = null;
}
}
public class CreateList{
protected Node head = null;
  protected Node tail = null;
//This function will add the new node at the end of the list.
public void add(T data){
//Create new node
Node newNode = new Node(data);
//Checks if the list is empty.
if(head == null){
head = newNode;
tail = newNode;
newNode.next = head;
}else{
//tail will point to new node.
tail.next = newNode;
//New node will become new tail.
tail = newNode;
//Since, it is circular linked list tail will point to head.
tail.next = head;
}
}
//Removes duplicate from the list
public void removeDuplicate() {
//Current will point to head
Node current = head, index = null, temp = null;
if(head == null) {
Console.WriteLine("List is empty");
}
else {
do{
//Temp will point to previous node of index.
temp = current;
//Index will point to node next to current
index = current.next;
while(index != head) {
//If current node is equal to index data
if(current.data.Equals(index.data)) {
//Here, index node is pointing to the node which is duplicate of current node
//Skips the duplicate node by pointing to next node
temp.next = index.next;
}
else{
//Temp will point to previous node of index.
temp = index;
}
index= index.next;
}
current =current.next;
}while(current.next != head); 
}
}
//Displays all the nodes in the list
public void display(){
Node current = head;
if(head == null){
Console.WriteLine("List is empty");
}
else{
do{
//Prints each node by incrementing pointer.
Console.Write(" "+ current.data);
current = current.next;
}while(current != head);
Console.WriteLine();
}
} 
}
public static void Main()
{
CreateList cl = new CreateList();
//Adds data to the list
cl.add(1);
cl.add(2);
cl.add(3);
cl.add(2);
cl.add(2);
cl.add(4);
Console.WriteLine("Originals list: ");
cl.display();
//Removes duplicate nodes
cl.removeDuplicate();
Console.WriteLine("List after removing duplicates: ");
cl.display();
} 
}
}

输出:

Originals list: 
 1 2 3 2 2 4
List after removing duplicates: 
 1 2 3 4

PHP:




data = $data;
        $this->next = NULL;
    }
}
class CreateList{
    //Declaring head and tail pointer as null.
    private $head;
    private $tail;
    function __construct(){
        $this->head = NULL;
        $this->tail = NULL;
    }
    //This function will add the new node at the end of the list.
    function add($data){
        //Create new node
        $newNode = new Node($data);
        //Checks if the list is empty.
        if($this->head == NULL){
            //If list is empty, both head and tail would point to new node.
            $this->head = $newNode;
            $this->tail = $newNode;
            $newNode->next = $this->head;
        }
        else{
            //tail will point to new node.
            $this->tail->next = $newNode;
            //New node will become new tail.
            $this->tail = $newNode;
            //Since, it is circular linked list tail will point to head.
            $this->tail->next = $this->head;
        }
    }
    
    //Removes duplicate from the list
function removeDuplicate() {
//Current will point to head
$current = $this->head;
if($this->head == NULL) {
echo "List is empty";
}
else {
do{
//Temp will point to previous node of index.
$temp = $current;
//Index will point to node next to current
$index = $current->next;
while($index != $this->head) {
//If current node is equal to index data
if($current->data == $index->data) {
//Here, index node is pointing to the node which is duplicate of current node
//Skips the duplicate node by pointing to next node
$temp->next = $index->next;
}
else {
//Temp will point to previous node of index.
$temp = $index;
}
$index= $index->next;
}
$current = $current->next;
}while($current->next != $this->head); 
}
}
    
    //Displays all the nodes in the list
    function display() {
        $current = $this->head;
        if($this->head == NULL) {
            echo "List is empty";
        }
        else {
             do{
                //Prints each node by incrementing pointer.
                echo(" $current->data");
                $current = $current->next;
            }while($current != $this->head);
            echo "
"; } } } $cl = new CreateList(); //Adds data to the list $cl->add(1); $cl->add(2); $cl->add(3); $cl->add(2); $cl->add(2); $cl->add(4); echo "Originals list:
"; $cl->display(); //Removes duplicate nodes $cl->removeDuplicate(); echo "List after removing duplicates:
"; $cl->display(); ?>

输出:

Originals list: 
 1 2 3 2 2 4
List after removing duplicates: 
 1 2 3 4