题解 | 2025/7/27（链表）（Java）

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) {
        int length1 = getLength(pHead1), length2 = getLength(pHead2);
        while (length1 < length2) {
            pHead2 = pHead2.next;
            length1++;
        }
        while (length1 > length2) {
            pHead1 = pHead1.next;
            length2++;
        }
        while (pHead1 != pHead2) {
            pHead1 = pHead1.next;
            pHead2 = pHead2.next;
        }
        return pHead1;
    }

    private static int getLength(ListNode head) {
        int length = 0;
        while (head != null) {
            length++;
            head = head.next;
        }
        return length;
    }
}