Encuentra el punto de intersección de dos listas enlazadas sin encontrar la longitud

Hay dos listas enlazadas individualmente en un sistema. Por algún error de programación, el Node final de una de las listas vinculadas se vinculó a la segunda lista, formando una lista en forma de Y invertida. Escriba un programa para obtener el punto donde ambas listas enlazadas se fusionan.

Ejemplos:  

Input: 1 -> 2 -> 3 -> 4 -> 5 -> 6
                      ^
                      |
            7 -> 8 -> 9
Output: 4

Input:         13 -> 14 -> 5 -> 6
                      ^
                      |
      10 -> 2 -> 3 -> 4 
Output: 14

Requisitos previos: escribir una función para obtener el punto de intersección de dos listas enlazadas

Enfoque: tome dos punteros para los encabezados de ambas listas vinculadas. Si uno de ellos llega al final antes, utilícelo moviéndolo al principio de la otra lista. Una vez que ambos pasen por la reasignación, estarán a la misma distancia del punto de colisión.

A continuación se muestra la implementación del enfoque anterior: 

C++

// C++ implementation of the approach
#include <bits/stdc++.h>
using namespace std;
 
/* Link list node */
class Node {
public:
    int data;
    Node* next;
};
 
// Function to return the intersection point
// of the two linked lists head1 and head2
int getIntesectionNode(Node* head1, Node* head2)
{
    Node* current1 = head1;
    Node* current2 = head2;
 
    // If one of the head is NULL
    if (!current1 or !current2)
        return -1;
 
    // Continue until we find intersection node
    while (current1 and current2
           and current1 != current2) {
        current1 = current1->next;
        current2 = current2->next;
 
        // If we get intersection node
        if (current1 == current2)
            return current1->data;
 
        // If one of them reaches end
        if (!current1)
            current1 = head2;
        if (!current2)
            current2 = head1;
    }
 
    return current1->data;
}
 
// Driver code
int main()
{
    /*
        Create two linked lists
     
        1st 3->6->9->15->30
        2nd 10->15->30
     
        15 is the intersection point
    */
 
    Node* newNode;
 
    // Addition of new nodes
    Node* head1 = new Node();
    head1->data = 10;
 
    Node* head2 = new Node();
    head2->data = 3;
 
    newNode = new Node();
    newNode->data = 6;
    head2->next = newNode;
 
    newNode = new Node();
    newNode->data = 9;
    head2->next->next = newNode;
 
    newNode = new Node();
    newNode->data = 15;
    head1->next = newNode;
    head2->next->next->next = newNode;
 
    newNode = new Node();
    newNode->data = 30;
    head1->next->next = newNode;
 
    head1->next->next->next = NULL;
 
    cout << getIntesectionNode(head1, head2);
 
    return 0;
}

Java

// Java implementation of the approach
class GFG
{
 
/* Link list node */
static class Node
{
 
    int data;
    Node next;
};
 
// Function to return the intersection point
// of the two linked lists head1 and head2
static int getIntesectionNode(Node head1, Node head2)
{
    Node current1 = head1;
    Node current2 = head2;
 
    // If one of the head is null
    if (current1 == null || current2 == null )
        return -1;
 
    // Continue until we find intersection node
    while (current1 != null && current2 != null
        && current1 != current2)
    {
        current1 = current1.next;
        current2 = current2.next;
 
        // If we get intersection node
        if (current1 == current2)
            return current1.data;
 
        // If one of them reaches end
        if (current1 == null )
            current1 = head2;
        if (current2 == null )
            current2 = head1;
    }
 
    return current1.data;
}
 
// Driver code
public static void main(String[] args)
{
    /*
        Create two linked lists
     
        1st 3.6.9.15.30
        2nd 10.15.30
     
        15 is the intersection point
    */
 
    Node newNode;
 
    // Addition of new nodes
    Node head1 = new Node();
    head1.data = 10;
 
    Node head2 = new Node();
    head2.data = 3;
 
    newNode = new Node();
    newNode.data = 6;
    head2.next = newNode;
 
    newNode = new Node();
    newNode.data = 9;
    head2.next.next = newNode;
 
    newNode = new Node();
    newNode.data = 15;
    head1.next = newNode;
    head2.next.next.next = newNode;
 
    newNode = new Node();
    newNode.data = 30;
    head1.next.next = newNode;
 
    head1.next.next.next = null;
 
    System.out.print(getIntesectionNode(head1, head2));
}
}
 
// This code is contributed by 29AjayKumar

Python3

# Python3 implementation of the approach
 
''' Link list node '''
class new_Node:
         
    # Constructor to initialize the node object
    def __init__(self, data):
        self.data = data
        self.next = None
 
# Function to return the intersection point
# of the two linked lists head1 and head2
def getIntesectionNode(head1, head2):
     
    current1 = head1
    current2 = head2
     
    # If one of the head is None
    if (not current1 or not current2 ):
        return -1
         
    # Continue until we find intersection node
    while (current1 and current2 and current1 != current2):
        current1 = current1.next
        current2 = current2.next
         
        # If we get intersection node
        if (current1 == current2):
            return current1.data
             
        # If one of them reaches end
        if (not current1):
            current1 = head2
         
        if (not current2):
            current2 = head1
             
    return current1.data
 
# Driver code
'''
    Create two linked lists
 
    1st 3.6.9.15.30
    2nd 10.15.30
 
    15 is the intersection po
'''
 
# Addition of newNodes
head1 = new_Node(10)
 
head2 = new_Node(3)
 
newNode = new_Node(6)
head2.next = newNode
 
newNode = new_Node(9)
head2.next.next = newNode
 
newNode = new_Node(15)
head1.next = newNode
head2.next.next.next = newNode
 
newNode = new_Node(30)
head1.next.next = newNode
 
head1.next.next.next = None
 
print(getIntesectionNode(head1, head2))
 
# This code is contributed by shubhamsingh10

C#

// C# implementation of the approach
using System;
 
class GFG
{
 
/* Link list node */
class Node
{
 
    public int data;
    public Node next;
};
 
// Function to return the intersection point
// of the two linked lists head1 and head2
static int getIntesectionNode(Node head1, Node head2)
{
    Node current1 = head1;
    Node current2 = head2;
 
    // If one of the head is null
    if (current1 == null || current2 == null )
        return -1;
 
    // Continue until we find intersection node
    while (current1 != null && current2 != null
        && current1 != current2)
    {
        current1 = current1.next;
        current2 = current2.next;
 
        // If we get intersection node
        if (current1 == current2)
            return current1.data;
 
        // If one of them reaches end
        if (current1 == null )
            current1 = head2;
        if (current2 == null )
            current2 = head1;
    }
 
    return current1.data;
}
 
// Driver code
public static void Main(String[] args)
{
    /*
        Create two linked lists
     
        1st 3.6.9.15.30
        2nd 10.15.30
     
        15 is the intersection point
    */
 
    Node newNode;
 
    // Addition of new nodes
    Node head1 = new Node();
    head1.data = 10;
 
    Node head2 = new Node();
    head2.data = 3;
 
    newNode = new Node();
    newNode.data = 6;
    head2.next = newNode;
 
    newNode = new Node();
    newNode.data = 9;
    head2.next.next = newNode;
 
    newNode = new Node();
    newNode.data = 15;
    head1.next = newNode;
    head2.next.next.next = newNode;
 
    newNode = new Node();
    newNode.data = 30;
    head1.next.next = newNode;
 
    head1.next.next.next = null;
 
    Console.Write(getIntesectionNode(head1, head2));
}
}
 
// This code is contributed by PrinciRaj1992

Javascript

<script>
// Javascript implementation of the approach
 
/* Link list node */
class Node {
 
    constructor()
    {
        this.data = 0;
        this.next = null;
    }
};
 
// Function to return the intersection point
// of the two linked lists head1 and head2
function getIntesectionNode(head1, head2)
{
    var current1 = head1;
    var current2 = head2;
 
    // If one of the head is null
    if (!current1 || !current2)
        return -1;
 
    // Continue until we find intersection node
    while (current1 && current2
           && current1 != current2) {
        current1 = current1.next;
        current2 = current2.next;
 
        // If we get intersection node
        if (current1 == current2)
            return current1.data;
 
        // If one of them reaches end
        if (!current1)
            current1 = head2;
        if (!current2)
            current2 = head1;
    }
 
    return current1.data;
}
 
// Driver code
/*
    Create two linked lists
 
    1st 3.6.9.15.30
    2nd 10.15.30
 
    15 is the intersection point
*/
var newNode;
 
// Addition of new nodes
var head1 = new Node();
head1.data = 10;
var head2 = new Node();
head2.data = 3;
newNode = new Node();
newNode.data = 6;
head2.next = newNode;
newNode = new Node();
newNode.data = 9;
head2.next.next = newNode;
newNode = new Node();
newNode.data = 15;
head1.next = newNode;
head2.next.next.next = newNode;
newNode = new Node();
newNode.data = 30;
head1.next.next = newNode;
head1.next.next.next = null;
document.write( getIntesectionNode(head1, head2));
 
// This code is contributed by noob2000.
</script>
Producción: 

15

 

Publicación traducida automáticamente

Artículo escrito por pawan_asipu y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA

Deja una respuesta

Tu dirección de correo electrónico no será publicada. Los campos obligatorios están marcados con *