两个链表的第一个公共结点

两个链表的第一个公共结点

题目描述

代码

[code]/*
public class ListNode {
    int val;
    ListNode next = null;

    ListNode(int val) {
        this.val = val;
    }
}
*/
public class Solution {

    public ListNode FindFirstCommonNode(ListNode pHead1, ListNode pHead2) {
         ListNode temp1=pHead1;
         ListNode temp2=pHead2;
         int length1= getLengt( temp1);
         int length2= getLengt( temp2);
         if(length1>length2){
              int count=length1-length2;
              int i=0;
              while(i!=count){
                  pHead1=pHead1.next;
                  i++;
              }
         }
          if(length1<length2){
              int count=length2-length1;
              int i=0;
              while(i!=count){
                  pHead2=pHead2.next;
                  i++;
              }
         }
         while(pHead1!=pHead2){
             pHead1=pHead1.next;
             pHead2=pHead2.next;
         }
         return pHead1;
    }
    public int  getLengt(ListNode pHead1){
        int length=0;
        while(pHead1!=null){
            length++;
            pHead1=pHead1.next;
        }
        return length;
    }
}