题解 | #两个链表的第一个公共结点#

import java.util.*;
/*
public class ListNode {
    int val;
    ListNode next = null;
    ListNode(int val) {
        this.val = val;
    }
}*/
public class Solution {
    public ListNode FindFirstCommonNode(ListNode pHead1, ListNode pHead2) {
        if (pHead1 == null || pHead2 == null) {
            return null;
        }
        ListNode p = pHead1, q = pHead2;
	  //类似把两个链表变得一样长，和快慢指针有一点点相似
        while (p != q) {
            p = p != null ? p.next : pHead2;
            q = q != null ? q.next : pHead1;
        }
        return p;
    }
}