题解 | #两个链表的第一个公共结点#

1. 获取链表长度，链表尾端对齐

        while (cur1) {
            len1++;
            cur1 = cur1->next;
        }
        while (cur2) {
            len2++;
            cur2 = cur2->next;
        }
        cur1 = pHead1;
        cur2 = pHead2;
        if (len1 < len2) {
            swap(len1, len2);
            swap(cur1, cur2);
        }
        int len1_2 = len1 - len2;
        while (len1_2--) {
            cur1 = cur1->next;
        }

2. 判断是否有相等的部分

        int len1_2 = len1 - len2;
        while (len1_2--) {
            cur1 = cur1->next;
        }
        while (cur1 && cur2) {
            if (cur1 == cur2) {
                return cur1;
            }
            cur1 = cur1->next;
            cur2 = cur2->next;
        }
        return NULL;