Dada una lista enlazada individualmente, encuentre el medio de la lista enlazada y establezca el Node medio de la lista enlazada al principio de la lista enlazada.
Ejemplos:
C++
// C++ program to make middle node as head of
// linked list.
#include <bits/stdc++.h>
using namespace std;
/* Link list node */
class Node
{
public:
int data;
Node* next;
};
/* Function to get the middle and set at
beginning of the linked list*/
void setMiddleHead(Node** head)
{
if (*head == NULL)
return;
// To traverse list nodes one by one
Node* one_node = (*head);
// To traverse list nodes by skipping
// one.
Node* two_node = (*head);
// To keep track of previous of middle
Node* prev = NULL;
while (two_node != NULL && two_node->next != NULL)
{
/* for previous node of middle node */
prev = one_node;
/* move one node each time*/
two_node = two_node->next->next;
/* move two node each time*/
one_node = one_node->next;
}
/* set middle node at head */
prev->next = prev->next->next;
one_node->next = (*head);
(*head) = one_node;
}
// To insert a node at the beginning of linked
// list.
void push(Node** head_ref, int new_data)
{
/* allocate node */
Node* new_node = new Node();
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;
}
// A function to print a given linked list
void printList(Node* ptr)
{
while (ptr != NULL)
{
cout << ptr->data << " ";
ptr = ptr->next;
}
cout<<endl;
}
/* Driver code*/
int main()
{
// Create a list of 5 nodes
Node* head = NULL;
int i;
for (i = 5; i > 0; i--)
push(&head, i);
cout << " list before: ";
printList(head);
setMiddleHead(&head);
cout << " list After: ";
printList(head);
return 0;
}
// This is code is contributed by rathbhupendra
C
// C program to make middle node as head of
// linked list.
#include <stdio.h>
#include <stdlib.h>
/* Link list node */
struct Node {
int data;
struct Node* next;
};
/* Function to get the middle and set at
beginning of the linked list*/
void setMiddleHead(struct Node** head)
{
if (*head == NULL)
return;
// To traverse list nodes one by one
struct Node* one_node = (*head);
// To traverse list nodes by skipping
// one.
struct Node* two_node = (*head);
// To keep track of previous of middle
struct Node* prev = NULL;
while (two_node != NULL && two_node->next != NULL) {
/* for previous node of middle node */
prev = one_node;
/* move one node each time*/
two_node = two_node->next->next;
/* move two node each time*/
one_node = one_node->next;
}
/* set middle node at head */
prev->next = prev->next->next;
one_node->next = (*head);
(*head) = one_node;
}
// To insert a node at the beginning of linked
// list.
void push(struct Node** head_ref, int new_data)
{
/* allocate node */
struct Node* new_node =
(struct Node*)malloc(sizeof(struct Node));
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;
}
// A function to print a given linked list
void printList(struct Node* ptr)
{
while (ptr != NULL) {
printf("%d ", ptr->data);
ptr = ptr->next;
}
printf("\n");
}
/* Driver function*/
int main()
{
// Create a list of 5 nodes
struct Node* head = NULL;
int i;
for (i = 5; i > 0; i--)
push(&head, i);
printf(" list before: ");
printList(head);
setMiddleHead(&head);
printf(" list After: ");
printList(head);
return 0;
}
Java
// Java program to make middle node
// as head of Linked list
public class GFG
{
/* Link list node */
static class Node {
int data;
Node next;
Node(int data){
this.data = data;
next = null;
}
}
static Node head;
/* Function to get the middle and
set at beginning of the linked list*/
static void setMiddleHead()
{
if (head == null)
return;
// To traverse list nodes one
// by one
Node one_node = head;
// To traverse list nodes by
// skipping one.
Node two_node = head;
// To keep track of previous of middle
Node prev = null;
while (two_node != null &&
two_node.next != null) {
/* for previous node of middle node */
prev = one_node;
/* move one node each time*/
two_node = two_node.next.next;
/* move two node each time*/
one_node = one_node.next;
}
/* set middle node at head */
prev.next = prev.next.next;
one_node.next = head;
head = one_node;
}
// To insert a node at the beginning of
// linked list.
static void push(int new_data)
{
/* allocate node */
Node new_node = new Node(new_data);
/* link the old list off the new node */
new_node.next = head;
/* move the head to point to the new node */
head = new_node;
}
// A function to print a given linked list
static void printList(Node ptr)
{
while (ptr != null) {
System.out.print(ptr.data+" ");
ptr = ptr.next;
}
System.out.println();
}
/* Driver function*/
public static void main(String args[])
{
// Create a list of 5 nodes
head = null;
int i;
for (i = 5; i > 0; i--)
push(i);
System.out.print(" list before: ");
printList(head);
setMiddleHead();
System.out.print(" list After: ");
printList(head);
}
}
// This code is contributed by Sumit Ghosh
Python3
# Python3 program to make middle node
# as head of Linked list
# Linked List node
class Node:
def __init__(self, data):
self.data = data
self.next = None
# function to get the middle node
# set it as the beginning of the
# linked list
def setMiddleHead(head):
if(head == None):
return None
# to traverse nodes
# one by one
one_node = head
# to traverse nodes by
# skipping one
two_node = head
# to keep track of previous middle
prev = None
while(two_node != None and
two_node.next != None):
# for previous node of middle node
prev = one_node
# move one node each time
one_node = one_node.next
# move two nodes each time
two_node = two_node.next.next
# set middle node at head
prev.next = prev.next.next
one_node.next = head
head = one_node
# return the modified head
return head
def push(head, new_data):
# allocate new node
new_node = Node(new_data)
#link the old list to new node
new_node.next = head
# move the head to point the new node
head = new_node
# return the modified head
return head
# A function to print a given linked list
def printList(head):
temp = head
while (temp!=None):
print(str(temp.data), end = " ")
temp = temp.next
print("")
# Create a list of 5 nodes
head = None
for i in range(5, 0, -1):
head = push(head, i)
print(" list before: ", end = "")
printList(head)
head = setMiddleHead(head)
print(" list After: ", end = "")
printList(head)
# This code is contributed
# by Pranav Devarakonda
C#
// C# program to make middle node
// as head of Linked list
using System;
public class GFG
{
/* Link list node */
class Node
{
public int data;
public Node next;
public Node(int data)
{
this.data = data;
next = null;
}
}
static Node head;
/* Function to get the middle and
set at beginning of the linked list*/
static void setMiddleHead()
{
if (head == null)
return;
// To traverse list nodes one
// by one
Node one_node = head;
// To traverse list nodes by
// skipping one.
Node two_node = head;
// To keep track of previous of middle
Node prev = null;
while (two_node != null &&
two_node.next != null)
{
/* for previous node of middle node */
prev = one_node;
/* move one node each time*/
two_node = two_node.next.next;
/* move two node each time*/
one_node = one_node.next;
}
/* set middle node at head */
prev.next = prev.next.next;
one_node.next = head;
head = one_node;
}
// To insert a node at the beginning of
// linked list.
static void push(int new_data)
{
/* allocate node */
Node new_node = new Node(new_data);
/* link the old list off the new node */
new_node.next = head;
/* move the head to point to the new node */
head = new_node;
}
// A function to print a given linked list
static void printList(Node ptr)
{
while (ptr != null) {
Console.Write(ptr.data + " ");
ptr = ptr.next;
}
Console.WriteLine();
}
/* Driver code*/
public static void Main(String []args)
{
// Create a list of 5 nodes
head = null;
int i;
for (i = 5; i > 0; i--)
push(i);
Console.Write(" list before: ");
printList(head);
setMiddleHead();
Console.Write(" list After: ");
printList(head);
}
}
// This code is contributed by Rajput-Ji
Javascript
<script>
// javascript program to make middle node
// as head of Linked list
/* Link list node */
class Node {
constructor(val) {
this.data = val;
this.next = null;
}
}
var head;
/*
* Function to get the middle and set at beginning of the linked list
*/
function setMiddleHead() {
if (head == null)
return;
// To traverse list nodes one
// by one
one_node = head;
// To traverse list nodes by
// skipping one.
two_node = head;
// To keep track of previous of middle
prev = null;
while (two_node != null && two_node.next != null) {
/* for previous node of middle node */
prev = one_node;
/* move one node each time */
two_node = two_node.next.next;
/* move two node each time */
one_node = one_node.next;
}
/* set middle node at head */
prev.next = prev.next.next;
one_node.next = head;
head = one_node;
}
// To insert a node at the beginning of
// linked list.
function push(new_data)
{
/* allocate node */
new_node = new Node(new_data);
/* link the old list off the new node */
new_node.next = head;
/* move the head to point to the new node */
head = new_node;
}
// A function to print a given linked list
function printList( ptr) {
while (ptr != null) {
document.write(ptr.data + " ");
ptr = ptr.next;
}
document.write("<br/>");
}
/* Driver function */
// Create a list of 5 nodes
head = null;
var i;
for (i = 5; i > 0; i--)
push(i);
document.write(" list before: ");
printList(head);
setMiddleHead();
document.write(" list After: ");
printList(head);
// This code is contributed by aashish1995
</script>
Publicación traducida automáticamente
Artículo escrito por GeeksforGeeks-1 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA