将所有零移到链表的前面

给定一个链表。任务是将所有 0 移到链表的前面。重新排列后，除 0 之外的所有其他元素的顺序应相同。
例子：

Input : 0 1 0 1 2 0 5 0 4 0
Output :0 0 0 0 0 1 1 2 5 4

Input :1 1 2 3 0 0 0 
Output :0 0 0 1 1 2 3

一个简单的解决方案是将所有链表元素存储在一个数组中。然后将数组的所有元素移动到开头。最后，将数组元素复制回链表。
一个有效的解决方案是从第二个节点遍历链表。对于每个值为 0 的节点，我们将其与其当前位置断开连接并将节点移到前面。

C++

// CPP program to move all zeros
// to the end of the linked list.
#include 
using namespace std;
 
/* Link list node */
struct Node {
  int data;
  struct Node *next;
};
 
/* Given a reference (pointer to pointer) to
the head of a list and an int, push a new
node on the front of the list. */
void push(struct Node **head_ref, int new_data) {
  struct Node *new_node = new Node;
  new_node->data = new_data;
  new_node->next = (*head_ref);
  (*head_ref) = new_node;
}
 
/* moving zeroes to the beginning in linked list */
void moveZeroes(struct Node **head) {
  if (*head == NULL)
    return;
 
  // Traverse the list from second node.
  struct Node *temp = (*head)->next, *prev = *head;
  while (temp != NULL) {
 
    // If current node is 0, move to
    // beginning of linked list
    if (temp->data == 0) {
 
      // Disconnect node from its
      // current position
      Node *curr = temp;
      temp = temp->next;
      prev->next = temp;
 
      // Move to beginning
      curr->next = (*head);
      *head = curr;
    }
 
    // For non-zero values
    else {
      prev = temp;
      temp = temp->next;
    }
  }
}
 
// function to displaying nodes
void display(struct Node *head) {
  while (head != NULL) {
    cout << head->data << "->";
    head = head->next;
  }
  cout << "NULL";
}
 
/* Driver program to test above function*/
int main() {
 
  /* Start with the empty list */
  struct Node *head = NULL;
 
  /* Use push() to construct below list
  0->0->1->0->1->0->2->0->3->0 */
  push(&head, 0);
  push(&head, 3);
  push(&head, 0);
  push(&head, 2);
  push(&head, 0);
  push(&head, 1);
  push(&head, 0);
  push(&head, 1);
  push(&head, 0);
  push(&head, 0);
 
  // displaying list before rearrangement
  cout << "Linked list before rearrangement\n";
  display(head);
 
  /* Check the move_zeroes function */
  moveZeroes(&head);
 
  // displaying list after rearrangement
  cout << "\n Linked list after rearrangement \n";
  display(head);
 
  return 0;
}

Java

// JAVA program to move all zeros
// to the end of the linked list.
class GFG
{
 
    /* Link list node */
    static class Node
    {
        int data;
        Node next;
    };
     
    /* Given a reference (pointer to pointer) to
    the head of a list and an int, push a new
    node on the front of the list. */
    static Node push(Node head_ref, int new_data)
    {
        Node new_node = new Node();
        new_node.data = new_data;
        new_node.next = head_ref;
        head_ref = new_node;
        return new_node;
    }
     
    /* moving zeroes to the beginning in linked list */
    static Node moveZeroes(Node head)
    {
        if (head == null)
            return null;
         
        // Traverse the list from second node.
        Node temp = (head).next, prev = head;
        while (temp != null)
        {
         
            // If current node is 0, move to
            // beginning of linked list
            if (temp.data == 0)
            {
         
                // Disconnect node from its
                // current position
                Node curr = temp;
                temp = temp.next;
                prev.next = temp;
             
                // Move to beginning
                curr.next = (head);
                head = curr;
            }
         
            // For non-zero values
            else
            {
                prev = temp;
                temp = temp.next;
            }
             
        }
        return head;
    }
     
    // function to displaying nodes
    static void display(Node head)
    {
        while (head != null)
        {
            System.out.print(head.data+ "->");
            head = head.next;
        }
        System.out.print("null");
    }
     
    /* Driver code*/
    public static void main(String[] args)
    {
     
        /* Start with the empty list */
        Node head = null;
         
        /* Use push() to conbelow list
        0.0.1.0.1.0.2.0.3.0 */
        head = push(head, 0);
        head = push(head, 3);
        head = push(head, 0);
        head = push(head, 2);
        head = push(head, 0);
        head = push(head, 1);
        head = push(head, 0);
        head = push(head, 1);
        head = push(head, 0);
        head = push(head, 0);
         
        // displaying list before rearrangement
        System.out.print("Linked list before rearrangement\n");
        display(head);
         
        /* Check the move_zeroes function */
        head = moveZeroes(head);
         
        // displaying list after rearrangement
        System.out.print("\n Linked list after rearrangement \n");
        display(head);
         
    }
}
 
// This code is contributed by PrinciRaj1992

Python3

# Python3 program to move all zeros
# to the end of the linked list.
  
''' Link list node '''
class Node:  
    def __init__(self, data):     
        self.data = data
        self.next = None
    
''' Given a reference (pointer to pointer) to
the head of a list and an int, push a new
node on the front of the list. '''
def push(head_ref, new_data):   
  new_node = Node(new_data)
  new_node.next = (head_ref);
  (head_ref) = new_node;
  return head_ref
  
''' moving zeroes to the beginning in linked list '''
def moveZeroes(head):
     
  if (head == None):
    return;
  
  # Traverse the list from second node.
  temp = head.next
  prev = head;
  while (temp != None):
  
    # If current node is 0, move to
    # beginning of linked list
    if (temp.data == 0):
  
      # Disconnect node from its
      # current position
      curr = temp;
      temp = temp.next;
      prev.next = temp;
  
      # Move to beginning
      curr.next = (head);
      head = curr;
     
    # For non-zero values
    else:
      prev = temp;
      temp = temp.next;
  return head
    
# function to displaying nodes
def display(head):
     
  while (head != None):
      print(head.data, end = '->')
      head = head.next;
   
  print('NULL', end = '')
    
''' Driver program to test above function'''
if __name__=='__main__':
  
  ''' Start with the empty list '''
  head = None;
  
  ''' Use push() to construct below list
  0.0.1.0.1.0.2.0.3.0 '''
  head = push(head, 0);
  head = push(head, 3);
  head = push(head, 0);
  head = push(head, 2);
  head = push(head, 0);
  head = push(head, 1);
  head = push(head, 0);
  head = push(head, 1);
  head = push(head, 0);
  head = push(head, 0);
  
  # displaying list before rearrangement
  print("Linked list before rearrangement");
  display(head);
  
  ''' Check the move_zeroes function '''
  head = moveZeroes(head);
  
  # displaying list after rearrangement
  print("\n\nLinked list after rearrangement ");
  display(head);
  
# This code is contributed by rutvik_56

C#

// C# program to move all zeros
// to the end of the linked list.
using System;
 
class GFG
{
 
    /* Link list node */
    class Node
    {
        public int data;
        public Node next;
    };
     
    /* Given a reference (pointer to pointer) to
    the head of a list and an int, push a new
    node on the front of the list. */
    static Node push(Node head_ref, int new_data)
    {
        Node new_node = new Node();
        new_node.data = new_data;
        new_node.next = head_ref;
        head_ref = new_node;
        return new_node;
    }
     
    /* moving zeroes to the beginning in linked list */
    static Node moveZeroes(Node head)
    {
        if (head == null)
            return null;
         
        // Traverse the list from second node.
        Node temp = (head).next, prev = head;
        while (temp != null)
        {
         
            // If current node is 0, move to
            // beginning of linked list
            if (temp.data == 0)
            {
         
                // Disconnect node from its
                // current position
                Node curr = temp;
                temp = temp.next;
                prev.next = temp;
             
                // Move to beginning
                curr.next = (head);
                head = curr;
            }
         
            // For non-zero values
            else
            {
                prev = temp;
                temp = temp.next;
            }
        }
        return head;
    }
     
    // function to displaying nodes
    static void display(Node head)
    {
        while (head != null)
        {
            Console.Write(head.data + "->");
            head = head.next;
        }
        Console.Write("null");
    }
     
    // Driver code
    public static void Main(String[] args)
    {
     
        /* Start with the empty list */
        Node head = null;
         
        /* Use push() to conbelow list
        0->0->1->0->1->0->2->0->3->0 */
        head = push(head, 0);
        head = push(head, 3);
        head = push(head, 0);
        head = push(head, 2);
        head = push(head, 0);
        head = push(head, 1);
        head = push(head, 0);
        head = push(head, 1);
        head = push(head, 0);
        head = push(head, 0);
         
        // displaying list before rearrangement
        Console.Write("Linked list before rearrangement\n");
        display(head);
         
        /* Check the move_zeroes function */
        head = moveZeroes(head);
         
        // displaying list after rearrangement
        Console.Write("\n Linked list after rearrangement \n");
        display(head);
    }
}
 
// This code is contributed by Rajput-Ji

Javascript

 
// JavaScript program to move all zeros
// to the end of the linked list.
 
/* Link list node */
class Node
{
    constructor()
    {
        this.data = 0;
        this.next = null;
    }
};
 
/* Given a reference (pointer to pointer) to
the head of a list and an int, push a new
node on the front of the list. */
function push(head_ref, new_data)
{
    var new_node = new Node();
    new_node.data = new_data;
    new_node.next = head_ref;
    head_ref = new_node;
    return new_node;
}
 
/* moving zeroes to the beginning in linked list */
function moveZeroes(head)
{
    if (head == null)
        return null;
     
    // Traverse the list from second node.
    var temp = (head).next, prev = head;
    while (temp != null)
    {
     
        // If current node is 0, move to
        // beginning of linked list
        if (temp.data == 0)
        {
     
            // Disconnect node from its
            // current position
            var curr = temp;
            temp = temp.next;
            prev.next = temp;
         
            // Move to beginning
            curr.next = (head);
            head = curr;
        }
     
        // For non-zero values
        else
        {
            prev = temp;
            temp = temp.next;
        }
    }
    return head;
}
 
// function to displaying nodes
function display(head)
{
    while (head != null)
    {
        document.write(head.data + "->");
        head = head.next;
    }
    document.write("null");
}
 
// Driver code
/* Start with the empty list */
var head = null;
 
/* Use push() to conbelow list
0->0->1->0->1->0->2->0->3->0 */
head = push(head, 0);
head = push(head, 3);
head = push(head, 0);
head = push(head, 2);
head = push(head, 0);
head = push(head, 1);
head = push(head, 0);
head = push(head, 1);
head = push(head, 0);
head = push(head, 0);
 
// displaying list before rearrangement
document.write("Linked list before rearrangement<br>");
display(head);
 
/* Check the move_zeroes function */
head = moveZeroes(head);
 
// displaying list after rearrangement
document.write("<br> Linked list after rearrangement <br>");
display(head);
 

输出：

Linked list before rearrangement
0->0->1->0->1->0->2->0->3->0->NULL

Linked list after rearrangement
0->0->0->0->0->0->1->1->2->3->NULL

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