单链表中的交替奇数和偶数节点
给定一个单链表,重新排列列表,使偶数和奇数节点在列表中交替出现。
这种重排有两种可能的形式。如果第一个数据是奇数,那么第二个节点必须是偶数。第三个节点必须是奇数,依此类推。请注意,第一个节点是偶数、第二个奇数、第三个偶数等的另一种排列也是可能的。
例子:
Input : 11 -> 20 -> 40 -> 55 -> 77 -> 80 -> NULL
Output : 11 -> 20 -> 55 -> 40 -> 77 -> 80 -> NULL
20, 40, 80 occur in even positions and 11, 55, 77
occur in odd positions.
Input : 10 -> 1 -> 2 -> 3 -> 5 -> 6 -> 7 -> 8 -> NULL
Output : 1 -> 10 -> 3 -> 2 -> 5 -> 6 -> 7 -> 8 -> NULL
1, 3, 5, 7 occur in odd positions and 10, 2, 6, 8 occur
at even positions in the list
方法1(简单)
在这种方法中,我们创建了两个堆栈——奇数和偶数。我们遍历列表,当我们在奇数位置遇到偶数节点时,我们将该节点的地址推入偶数堆栈。如果我们在偶数位置遇到一个奇数节点,我们将该节点的地址推送到奇数堆栈。
遍历列表后,我们只需弹出两个堆栈顶部的节点并交换它们的数据。我们不断重复此步骤,直到堆栈变空。
Step 1: Create two stacks Odd and Even. These stacks will store the pointers to the nodes in the list
Step 2: Traverse list from start to end, using the variable current. Repeat following steps 3-4
Step 3: If current node is even and it occurs at an odd position, push this node’s address to stack Even
Step 4: If current node is odd and it occurs at an even position, push this node’s address to stack Odd.
[END OF TRAVERSAL]
Step 5: The size of both the stacks will be same. While both the stacks are not empty exchange the nodes at the top of the two stacks, and pop both nodes from their respective stacks.
Step 6: The List is now rearranged. STOP
C++
// CPP program to rearrange nodes
// as alternate odd even nodes in
// a Singly Linked List
#include
using namespace std;
// Structure node
struct Node {
int data;
struct Node* next;
};
// A utility function to print
// linked list
void printList(struct Node* node)
{
while (node != NULL) {
cout << node->data << " ";
node = node->next;
}
cout << endl;
}
// Function to create newNode
// in a linkedlist
Node* newNode(int key)
{
Node* temp = new Node;
temp->data = key;
temp->next = NULL;
return temp;
}
// Function to insert at beginning
Node* insertBeg(Node* head, int val)
{
Node* temp = newNode(val);
temp->next = head;
head = temp;
return head;
}
// Function to rearrange the
// odd and even nodes
void rearrangeOddEven(Node* head)
{
stack odd;
stack even;
int i = 1;
while (head != nullptr) {
if (head->data % 2 != 0 && i % 2 == 0) {
// Odd Value in Even Position
// Add pointer to current node
// in odd stack
odd.push(head);
}
else if (head->data % 2 == 0 && i % 2 != 0) {
// Even Value in Odd Position
// Add pointer to current node
// in even stack
even.push(head);
}
head = head->next;
i++;
}
while (!odd.empty() && !even.empty()) {
// Swap Data at the top of two stacks
swap(odd.top()->data, even.top()->data);
odd.pop();
even.pop();
}
}
// Driver code
int main()
{
Node* head = newNode(8);
head = insertBeg(head, 7);
head = insertBeg(head, 6);
head = insertBeg(head, 5);
head = insertBeg(head, 3);
head = insertBeg(head, 2);
head = insertBeg(head, 1);
cout << "Linked List:" << endl;
printList(head);
rearrangeOddEven(head);
cout << "Linked List after "
<< "Rearranging:" << endl;
printList(head);
return 0;
}
Java
// Java program to rearrange nodes
// as alternate odd even nodes in
// a Singly Linked List
import java.util.*;
class GFG
{
// class node
static class Node
{
int data;
Node next;
}
// A utility function to print
// linked list
static void printList(Node node)
{
while (node != null)
{
System.out.print(node.data +" ");
node = node.next;
}
System.out.println();
}
// Function to create newNode
// in a linkedlist
static Node newNode(int key)
{
Node temp = new Node();
temp.data = key;
temp.next = null;
return temp;
}
// Function to insert at beginning
static Node insertBeg(Node head, int val)
{
Node temp = newNode(val);
temp.next = head;
head = temp;
return head;
}
// Function to rearrange the
// odd and even nodes
static void rearrangeOddEven(Node head)
{
Stack odd=new Stack();
Stack even=new Stack();
int i = 1;
while (head != null) {
if (head.data % 2 != 0 && i % 2 == 0)
{
// Odd Value in Even Position
// Add pointer to current node
// in odd stack
odd.push(head);
}
else if (head.data % 2 == 0 && i % 2 != 0)
{
// Even Value in Odd Position
// Add pointer to current node
// in even stack
even.push(head);
}
head = head.next;
i++;
}
while (odd.size() > 0 && even.size() > 0)
{
// Swap Data at the top of two stacks
int k=odd.peek().data;
odd.peek().data=even.peek().data;
even.peek().data=k;
odd.pop();
even.pop();
}
}
// Driver code
public static void main(String args[])
{
Node head = newNode(8);
head = insertBeg(head, 7);
head = insertBeg(head, 6);
head = insertBeg(head, 5);
head = insertBeg(head, 3);
head = insertBeg(head, 2);
head = insertBeg(head, 1);
System.out.println( "Linked List:" );
printList(head);
rearrangeOddEven(head);
System.out.println( "Linked List after "+
"Rearranging:" );
printList(head);
}
}
// This contributed by Arnab Kundu
Python
# Python program to rearrange nodes
# as alternate odd even nodes in
# a Singly Linked List
# Link list node
class Node:
def __init__(self, data):
self.data = data
self.next = next
# A utility function to print
# linked list
def printList( node):
while (node != None) :
print(node.data , end=" ")
node = node.next
print("\n")
# Function to create newNode
# in a linkedlist
def newNode(key):
temp = Node(0)
temp.data = key
temp.next = None
return temp
# Function to insert at beginning
def insertBeg(head, val):
temp = newNode(val)
temp.next = head
head = temp
return head
# Function to rearrange the
# odd and even nodes
def rearrangeOddEven( head):
odd = []
even = []
i = 1
while (head != None):
if (head.data % 2 != 0 and i % 2 == 0):
# Odd Value in Even Position
# Add pointer to current node
# in odd stack
odd.append(head)
elif (head.data % 2 == 0 and i % 2 != 0):
# Even Value in Odd Position
# Add pointer to current node
# in even stack
even.append(head)
head = head.next
i = i + 1
while (len(odd) != 0 and len(even) != 0) :
# Swap Data at the top of two stacks
odd[-1].data, even[-1].data = even[-1].data, odd[-1].data
odd.pop()
even.pop()
return head
# Driver code
head = newNode(8)
head = insertBeg(head, 7)
head = insertBeg(head, 6)
head = insertBeg(head, 5)
head = insertBeg(head, 3)
head = insertBeg(head, 2)
head = insertBeg(head, 1)
print( "Linked List:" )
printList(head)
rearrangeOddEven(head)
print( "Linked List after ", "Rearranging:" )
printList(head)
# This code is contributed by Arnab Kundu
C#
// C# program to rearrange nodes
// as alternate odd even nodes in
// a Singly Linked List
using System;
using System.Collections.Generic;
class GFG
{
// class node
public class Node
{
public int data;
public Node next;
}
// A utility function to print
// linked list
static void printList(Node node)
{
while (node != null)
{
Console.Write(node.data +" ");
node = node.next;
}
Console.WriteLine();
}
// Function to create newNode
// in a linkedlist
static Node newNode(int key)
{
Node temp = new Node();
temp.data = key;
temp.next = null;
return temp;
}
// Function to insert at beginning
static Node insertBeg(Node head, int val)
{
Node temp = newNode(val);
temp.next = head;
head = temp;
return head;
}
// Function to rearrange the
// odd and even nodes
static void rearrangeOddEven(Node head)
{
Stack odd = new Stack();
Stack even = new Stack();
int i = 1;
while (head != null)
{
if (head.data % 2 != 0 && i % 2 == 0)
{
// Odd Value in Even Position
// Add pointer to current node
// in odd stack
odd.Push(head);
}
else if (head.data % 2 == 0 && i % 2 != 0)
{
// Even Value in Odd Position
// Add pointer to current node
// in even stack
even.Push(head);
}
head = head.next;
i++;
}
while (odd.Count > 0 && even.Count > 0)
{
// Swap Data at the top of two stacks
int k=odd.Peek().data;
odd.Peek().data=even.Peek().data;
even.Peek().data=k;
odd.Pop();
even.Pop();
}
}
// Driver code
public static void Main(String []args)
{
Node head = newNode(8);
head = insertBeg(head, 7);
head = insertBeg(head, 6);
head = insertBeg(head, 5);
head = insertBeg(head, 3);
head = insertBeg(head, 2);
head = insertBeg(head, 1);
Console.WriteLine( "Linked List:" );
printList(head);
rearrangeOddEven(head);
Console.WriteLine( "Linked List after "+
"Rearranging:" );
printList(head);
}
}
// This code has been contributed by 29AjayKumar
Javascript
C++
// Cpp program to rearrange nodes
// as alternate odd even nodes in
// a Singly Linked List
#include
using namespace std;
// Structure node
struct Node {
int data;
struct Node* next;
};
// A utility function to print
// linked list
void printList(struct Node* node)
{
while (node != NULL) {
cout << node->data << " ";
node = node->next;
}
cout << endl;
}
// Function to create newNode
// in a linkedlist
Node* newNode(int key)
{
Node* temp = new Node;
temp->data = key;
temp->next = NULL;
return temp;
}
// Function to insert at beginning
Node* insertBeg(Node* head, int val)
{
Node* temp = newNode(val);
temp->next = head;
head = temp;
return head;
}
// Function to rearrange the
// odd and even nodes
void rearrange(Node** head)
{
// Step 1: Segregate even and odd nodes
// Step 2: Split odd and even lists
// Step 3: Merge even list into odd list
Node* even;
Node *temp, *prev_temp;
Node *i, *j, *k, *l, *ptr;
// Step 1: Segregate Odd and Even Nodes
temp = (*head)->next;
prev_temp = *head;
while (temp != nullptr) {
// Backup next pointer of temp
Node* x = temp->next;
// If temp is odd move the node
// to beginning of list
if (temp->data % 2 != 0) {
prev_temp->next = x;
temp->next = (*head);
(*head) = temp;
}
else {
prev_temp = temp;
}
// Advance Temp Pointer
temp = x;
}
// Step 2
// Split the List into Odd and even
temp = (*head)->next;
prev_temp = (*head);
while (temp != nullptr && temp->data % 2 != 0) {
prev_temp = temp;
temp = temp->next;
}
even = temp;
// End the odd List (Make last node null)
prev_temp->next = nullptr;
// Step 3:
// Merge Even List into odd
i = *head;
j = even;
while (j != nullptr && i != nullptr) {
// While both lists are not
// exhausted Backup next
// pointers of i and j
k = i->next;
l = j->next;
i->next = j;
j->next = k;
// ptr points to the latest node added
ptr = j;
// Advance i and j pointers
i = k;
j = l;
}
if (i == nullptr) {
// Odd list exhausts before even,
// append remainder of even list to odd.
ptr->next = j;
}
// The case where even list exhausts before
// odd list is automatically handled since we
// merge the even list into the odd list
}
// Driver Code
int main()
{
Node* head = newNode(8);
head = insertBeg(head, 7);
head = insertBeg(head, 6);
head = insertBeg(head, 3);
head = insertBeg(head, 5);
head = insertBeg(head, 1);
head = insertBeg(head, 2);
head = insertBeg(head, 10);
cout << "Linked List:" << endl;
printList(head);
cout << "Rearranged List" << endl;
rearrange(&head);
printList(head);
}
Java
// Java program to rearrange nodes
// as alternate odd even nodes in
// a Singly Linked List
class GFG
{
// Structure node
static class Node
{
int data;
Node next;
};
// A utility function to print
// linked list
static void printList(Node node)
{
while (node != null)
{
System.out.print(node.data + " ");
node = node.next;
}
System.out.println();
}
// Function to create newNode
// in a linkedlist
static Node newNode(int key)
{
Node temp = new Node();
temp.data = key;
temp.next = null;
return temp;
}
// Function to insert at beginning
static Node insertBeg(Node head, int val)
{
Node temp = newNode(val);
temp.next = head;
head = temp;
return head;
}
// Function to rearrange the
// odd and even nodes
static Node rearrange(Node head)
{
// Step 1: Segregate even and odd nodes
// Step 2: Split odd and even lists
// Step 3: Merge even list into odd list
Node even;
Node temp, prev_temp;
Node i, j, k, l, ptr=null;
// Step 1: Segregate Odd and Even Nodes
temp = (head).next;
prev_temp = head;
while (temp != null)
{
// Backup next pointer of temp
Node x = temp.next;
// If temp is odd move the node
// to beginning of list
if (temp.data % 2 != 0)
{
prev_temp.next = x;
temp.next = (head);
(head) = temp;
}
else
{
prev_temp = temp;
}
// Advance Temp Pointer
temp = x;
}
// Step 2
// Split the List into Odd and even
temp = (head).next;
prev_temp = (head);
while (temp != null && temp.data % 2 != 0)
{
prev_temp = temp;
temp = temp.next;
}
even = temp;
// End the odd List (Make last node null)
prev_temp.next = null;
// Step 3:
// Merge Even List into odd
i = head;
j = even;
while (j != null && i != null)
{
// While both lists are not
// exhausted Backup next
// pointers of i and j
k = i.next;
l = j.next;
i.next = j;
j.next = k;
// ptr points to the latest node added
ptr = j;
// Advance i and j pointers
i = k;
j = l;
}
if (i == null)
{
// Odd list exhausts before even,
// append remainder of even list to odd.
ptr.next = j;
}
// The case where even list exhausts before
// odd list is automatically handled since we
// merge the even list into the odd list
return head;
}
// Driver Code
public static void main(String args[])
{
Node head = newNode(8);
head = insertBeg(head, 7);
head = insertBeg(head, 6);
head = insertBeg(head, 3);
head = insertBeg(head, 5);
head = insertBeg(head, 1);
head = insertBeg(head, 2);
head = insertBeg(head, 10);
System.out.println("Linked List:" );
printList(head);
System.out.println("Rearranged List" );
head=rearrange(head);
printList(head);
}
}
// This code is contributed by Arnab Kundu
Python3
# Python3 program to rearrange nodes
# as alternate odd even nodes in
# a Singly Linked List
# Structure node
class Node :
def __init__(self):
self.data = 0
self.next = None
# A utility function to print
# linked list
def printList(node) :
while (node != None) :
print(node.data, end = " ")
node = node.next
print(" ")
# Function to create newNode
# in a linkedlist
def newNode( key) :
temp = Node()
temp.data = key
temp.next = None
return temp
# Function to insert at beginning
def insertBeg( head, val) :
temp = newNode(val)
temp.next = head
head = temp
return head
# Function to rearrange the
# odd and even nodes
def rearrange(head) :
# Step 1: Segregate even and odd nodes
# Step 2: Split odd and even lists
# Step 3: Merge even list into odd list
even = None
temp = None
prev_temp = None
i = None
j = None
k = None
l = None
ptr = None
# Step 1: Segregate Odd and Even Nodes
temp = (head).next
prev_temp = head
while (temp != None) :
# Backup next pointer of temp
x = temp.next
# If temp is odd move the node
# to beginning of list
if (temp.data % 2 != 0) :
prev_temp.next = x
temp.next = (head)
(head) = temp
else:
prev_temp = temp
# Advance Temp Pointer
temp = x
# Step 2
# Split the List into Odd and even
temp = (head).next
prev_temp = (head)
while (temp != None and temp.data % 2 != 0) :
prev_temp = temp
temp = temp.next
even = temp
# End the odd List (Make last node None)
prev_temp.next = None
# Step 3:
# Merge Even List into odd
i = head
j = even
while (j != None and i != None):
# While both lists are not
# exhausted Backup next
# pointers of i and j
k = i.next
l = j.next
i.next = j
j.next = k
# ptr points to the latest node added
ptr = j
# Advance i and j pointers
i = k
j = l
if (i == None):
# Odd list exhausts before even,
# append remainder of even list to odd.
ptr.next = j
# The case where even list exhausts before
# odd list is automatically handled since we
# merge the even list into the odd list
return head
# Driver Code
head = newNode(8)
head = insertBeg(head, 7)
head = insertBeg(head, 6)
head = insertBeg(head, 3)
head = insertBeg(head, 5)
head = insertBeg(head, 1)
head = insertBeg(head, 2)
head = insertBeg(head, 10)
print("Linked List:" )
printList(head)
print("Rearranged List" )
head = rearrange(head)
printList(head)
# This code is contributed by Arnab Kundu
C#
// C# program to rearrange nodes
// as alternate odd even nodes in
// a Singly Linked List
using System;
class GFG
{
// Structure node
public class Node
{
public int data;
public Node next;
};
// A utility function to print
// linked list
static void printList(Node node)
{
while (node != null)
{
Console.Write(node.data + " ");
node = node.next;
}
Console.WriteLine();
}
// Function to create newNode
// in a linkedlist
static Node newNode(int key)
{
Node temp = new Node();
temp.data = key;
temp.next = null;
return temp;
}
// Function to insert at beginning
static Node insertBeg(Node head, int val)
{
Node temp = newNode(val);
temp.next = head;
head = temp;
return head;
}
// Function to rearrange the
// odd and even nodes
static Node rearrange(Node head)
{
// Step 1: Segregate even and odd nodes
// Step 2: Split odd and even lists
// Step 3: Merge even list into odd list
Node even;
Node temp, prev_temp;
Node i, j, k, l, ptr=null;
// Step 1: Segregate Odd and Even Nodes
temp = (head).next;
prev_temp = head;
while (temp != null)
{
// Backup next pointer of temp
Node x = temp.next;
// If temp is odd move the node
// to beginning of list
if (temp.data % 2 != 0)
{
prev_temp.next = x;
temp.next = (head);
(head) = temp;
}
else
{
prev_temp = temp;
}
// Advance Temp Pointer
temp = x;
}
// Step 2
// Split the List into Odd and even
temp = (head).next;
prev_temp = (head);
while (temp != null && temp.data % 2 != 0)
{
prev_temp = temp;
temp = temp.next;
}
even = temp;
// End the odd List (Make last node null)
prev_temp.next = null;
// Step 3:
// Merge Even List into odd
i = head;
j = even;
while (j != null && i != null)
{
// While both lists are not
// exhausted Backup next
// pointers of i and j
k = i.next;
l = j.next;
i.next = j;
j.next = k;
// ptr points to the latest node added
ptr = j;
// Advance i and j pointers
i = k;
j = l;
}
if (i == null)
{
// Odd list exhausts before even,
// append remainder of even list to odd.
ptr.next = j;
}
// The case where even list exhausts before
// odd list is automatically handled since we
// merge the even list into the odd list
return head;
}
// Driver Code
public static void Main(String []args)
{
Node head = newNode(8);
head = insertBeg(head, 7);
head = insertBeg(head, 6);
head = insertBeg(head, 3);
head = insertBeg(head, 5);
head = insertBeg(head, 1);
head = insertBeg(head, 2);
head = insertBeg(head, 10);
Console.WriteLine("Linked List:" );
printList(head);
Console.WriteLine("Rearranged List" );
head=rearrange(head);
printList(head);
}
}
// This code is contributed by Rajput-Ji
Javascript
Linked List:
1 2 3 5 6 7 8
Linked List after Rearranging:
1 2 3 6 5 8 7
时间复杂度: O(n)
辅助空间: O(n)
方法二(高效)
- 分离列表中的奇数和偶数值。在此之后,所有奇数将一起出现,然后是所有偶数。
- 将列表拆分为奇数和偶数两个列表。
- 将偶数列表合并为奇数列表
REARRANGE (HEAD)
Step 1: Traverse the list using NODE TEMP.
If TEMP is odd
Add TEMP to the beginning of the List
[END OF IF]
[END OF TRAVERSAL]
Step 2: Set TEMP to 2nd element of LIST.
Step 3: Set PREV_TEMP to 1st element of List
Step 4: Traverse using node TEMP as long as an even
node is not encountered.
PREV_TEMP = TEMP, TEMP = TEMP->NEXT
[END OF TRAVERSAL]
Step 5: Set EVEN to TEMP. Set PREV_TEMP->NEXT to NULL
Step 6: I = HEAD, J = EVEN
Step 7: Repeat while I != NULL and J != NULL
Store next nodes of I and J in K and L
K = I->NEXT, L = J->NEXT
I->NEXT = J, J->NEXT = K, PTR = J
I = K and J = L
[END OF LOOP]
Step 8: if I == NULL
PTR->NEXT = J
[END of IF]
Step 8: Return HEAD.
Step 9: End
C++
// Cpp program to rearrange nodes
// as alternate odd even nodes in
// a Singly Linked List
#include
using namespace std;
// Structure node
struct Node {
int data;
struct Node* next;
};
// A utility function to print
// linked list
void printList(struct Node* node)
{
while (node != NULL) {
cout << node->data << " ";
node = node->next;
}
cout << endl;
}
// Function to create newNode
// in a linkedlist
Node* newNode(int key)
{
Node* temp = new Node;
temp->data = key;
temp->next = NULL;
return temp;
}
// Function to insert at beginning
Node* insertBeg(Node* head, int val)
{
Node* temp = newNode(val);
temp->next = head;
head = temp;
return head;
}
// Function to rearrange the
// odd and even nodes
void rearrange(Node** head)
{
// Step 1: Segregate even and odd nodes
// Step 2: Split odd and even lists
// Step 3: Merge even list into odd list
Node* even;
Node *temp, *prev_temp;
Node *i, *j, *k, *l, *ptr;
// Step 1: Segregate Odd and Even Nodes
temp = (*head)->next;
prev_temp = *head;
while (temp != nullptr) {
// Backup next pointer of temp
Node* x = temp->next;
// If temp is odd move the node
// to beginning of list
if (temp->data % 2 != 0) {
prev_temp->next = x;
temp->next = (*head);
(*head) = temp;
}
else {
prev_temp = temp;
}
// Advance Temp Pointer
temp = x;
}
// Step 2
// Split the List into Odd and even
temp = (*head)->next;
prev_temp = (*head);
while (temp != nullptr && temp->data % 2 != 0) {
prev_temp = temp;
temp = temp->next;
}
even = temp;
// End the odd List (Make last node null)
prev_temp->next = nullptr;
// Step 3:
// Merge Even List into odd
i = *head;
j = even;
while (j != nullptr && i != nullptr) {
// While both lists are not
// exhausted Backup next
// pointers of i and j
k = i->next;
l = j->next;
i->next = j;
j->next = k;
// ptr points to the latest node added
ptr = j;
// Advance i and j pointers
i = k;
j = l;
}
if (i == nullptr) {
// Odd list exhausts before even,
// append remainder of even list to odd.
ptr->next = j;
}
// The case where even list exhausts before
// odd list is automatically handled since we
// merge the even list into the odd list
}
// Driver Code
int main()
{
Node* head = newNode(8);
head = insertBeg(head, 7);
head = insertBeg(head, 6);
head = insertBeg(head, 3);
head = insertBeg(head, 5);
head = insertBeg(head, 1);
head = insertBeg(head, 2);
head = insertBeg(head, 10);
cout << "Linked List:" << endl;
printList(head);
cout << "Rearranged List" << endl;
rearrange(&head);
printList(head);
}
Java
// Java program to rearrange nodes
// as alternate odd even nodes in
// a Singly Linked List
class GFG
{
// Structure node
static class Node
{
int data;
Node next;
};
// A utility function to print
// linked list
static void printList(Node node)
{
while (node != null)
{
System.out.print(node.data + " ");
node = node.next;
}
System.out.println();
}
// Function to create newNode
// in a linkedlist
static Node newNode(int key)
{
Node temp = new Node();
temp.data = key;
temp.next = null;
return temp;
}
// Function to insert at beginning
static Node insertBeg(Node head, int val)
{
Node temp = newNode(val);
temp.next = head;
head = temp;
return head;
}
// Function to rearrange the
// odd and even nodes
static Node rearrange(Node head)
{
// Step 1: Segregate even and odd nodes
// Step 2: Split odd and even lists
// Step 3: Merge even list into odd list
Node even;
Node temp, prev_temp;
Node i, j, k, l, ptr=null;
// Step 1: Segregate Odd and Even Nodes
temp = (head).next;
prev_temp = head;
while (temp != null)
{
// Backup next pointer of temp
Node x = temp.next;
// If temp is odd move the node
// to beginning of list
if (temp.data % 2 != 0)
{
prev_temp.next = x;
temp.next = (head);
(head) = temp;
}
else
{
prev_temp = temp;
}
// Advance Temp Pointer
temp = x;
}
// Step 2
// Split the List into Odd and even
temp = (head).next;
prev_temp = (head);
while (temp != null && temp.data % 2 != 0)
{
prev_temp = temp;
temp = temp.next;
}
even = temp;
// End the odd List (Make last node null)
prev_temp.next = null;
// Step 3:
// Merge Even List into odd
i = head;
j = even;
while (j != null && i != null)
{
// While both lists are not
// exhausted Backup next
// pointers of i and j
k = i.next;
l = j.next;
i.next = j;
j.next = k;
// ptr points to the latest node added
ptr = j;
// Advance i and j pointers
i = k;
j = l;
}
if (i == null)
{
// Odd list exhausts before even,
// append remainder of even list to odd.
ptr.next = j;
}
// The case where even list exhausts before
// odd list is automatically handled since we
// merge the even list into the odd list
return head;
}
// Driver Code
public static void main(String args[])
{
Node head = newNode(8);
head = insertBeg(head, 7);
head = insertBeg(head, 6);
head = insertBeg(head, 3);
head = insertBeg(head, 5);
head = insertBeg(head, 1);
head = insertBeg(head, 2);
head = insertBeg(head, 10);
System.out.println("Linked List:" );
printList(head);
System.out.println("Rearranged List" );
head=rearrange(head);
printList(head);
}
}
// This code is contributed by Arnab Kundu
Python3
# Python3 program to rearrange nodes
# as alternate odd even nodes in
# a Singly Linked List
# Structure node
class Node :
def __init__(self):
self.data = 0
self.next = None
# A utility function to print
# linked list
def printList(node) :
while (node != None) :
print(node.data, end = " ")
node = node.next
print(" ")
# Function to create newNode
# in a linkedlist
def newNode( key) :
temp = Node()
temp.data = key
temp.next = None
return temp
# Function to insert at beginning
def insertBeg( head, val) :
temp = newNode(val)
temp.next = head
head = temp
return head
# Function to rearrange the
# odd and even nodes
def rearrange(head) :
# Step 1: Segregate even and odd nodes
# Step 2: Split odd and even lists
# Step 3: Merge even list into odd list
even = None
temp = None
prev_temp = None
i = None
j = None
k = None
l = None
ptr = None
# Step 1: Segregate Odd and Even Nodes
temp = (head).next
prev_temp = head
while (temp != None) :
# Backup next pointer of temp
x = temp.next
# If temp is odd move the node
# to beginning of list
if (temp.data % 2 != 0) :
prev_temp.next = x
temp.next = (head)
(head) = temp
else:
prev_temp = temp
# Advance Temp Pointer
temp = x
# Step 2
# Split the List into Odd and even
temp = (head).next
prev_temp = (head)
while (temp != None and temp.data % 2 != 0) :
prev_temp = temp
temp = temp.next
even = temp
# End the odd List (Make last node None)
prev_temp.next = None
# Step 3:
# Merge Even List into odd
i = head
j = even
while (j != None and i != None):
# While both lists are not
# exhausted Backup next
# pointers of i and j
k = i.next
l = j.next
i.next = j
j.next = k
# ptr points to the latest node added
ptr = j
# Advance i and j pointers
i = k
j = l
if (i == None):
# Odd list exhausts before even,
# append remainder of even list to odd.
ptr.next = j
# The case where even list exhausts before
# odd list is automatically handled since we
# merge the even list into the odd list
return head
# Driver Code
head = newNode(8)
head = insertBeg(head, 7)
head = insertBeg(head, 6)
head = insertBeg(head, 3)
head = insertBeg(head, 5)
head = insertBeg(head, 1)
head = insertBeg(head, 2)
head = insertBeg(head, 10)
print("Linked List:" )
printList(head)
print("Rearranged List" )
head = rearrange(head)
printList(head)
# This code is contributed by Arnab Kundu
C#
// C# program to rearrange nodes
// as alternate odd even nodes in
// a Singly Linked List
using System;
class GFG
{
// Structure node
public class Node
{
public int data;
public Node next;
};
// A utility function to print
// linked list
static void printList(Node node)
{
while (node != null)
{
Console.Write(node.data + " ");
node = node.next;
}
Console.WriteLine();
}
// Function to create newNode
// in a linkedlist
static Node newNode(int key)
{
Node temp = new Node();
temp.data = key;
temp.next = null;
return temp;
}
// Function to insert at beginning
static Node insertBeg(Node head, int val)
{
Node temp = newNode(val);
temp.next = head;
head = temp;
return head;
}
// Function to rearrange the
// odd and even nodes
static Node rearrange(Node head)
{
// Step 1: Segregate even and odd nodes
// Step 2: Split odd and even lists
// Step 3: Merge even list into odd list
Node even;
Node temp, prev_temp;
Node i, j, k, l, ptr=null;
// Step 1: Segregate Odd and Even Nodes
temp = (head).next;
prev_temp = head;
while (temp != null)
{
// Backup next pointer of temp
Node x = temp.next;
// If temp is odd move the node
// to beginning of list
if (temp.data % 2 != 0)
{
prev_temp.next = x;
temp.next = (head);
(head) = temp;
}
else
{
prev_temp = temp;
}
// Advance Temp Pointer
temp = x;
}
// Step 2
// Split the List into Odd and even
temp = (head).next;
prev_temp = (head);
while (temp != null && temp.data % 2 != 0)
{
prev_temp = temp;
temp = temp.next;
}
even = temp;
// End the odd List (Make last node null)
prev_temp.next = null;
// Step 3:
// Merge Even List into odd
i = head;
j = even;
while (j != null && i != null)
{
// While both lists are not
// exhausted Backup next
// pointers of i and j
k = i.next;
l = j.next;
i.next = j;
j.next = k;
// ptr points to the latest node added
ptr = j;
// Advance i and j pointers
i = k;
j = l;
}
if (i == null)
{
// Odd list exhausts before even,
// append remainder of even list to odd.
ptr.next = j;
}
// The case where even list exhausts before
// odd list is automatically handled since we
// merge the even list into the odd list
return head;
}
// Driver Code
public static void Main(String []args)
{
Node head = newNode(8);
head = insertBeg(head, 7);
head = insertBeg(head, 6);
head = insertBeg(head, 3);
head = insertBeg(head, 5);
head = insertBeg(head, 1);
head = insertBeg(head, 2);
head = insertBeg(head, 10);
Console.WriteLine("Linked List:" );
printList(head);
Console.WriteLine("Rearranged List" );
head=rearrange(head);
printList(head);
}
}
// This code is contributed by Rajput-Ji
Javascript
Linked List:
10 2 1 5 3 6 7 8
Rearranged List
7 10 3 2 5 6 1 8
时间复杂度: O(n)
辅助空间: O(1)