题解 | #两个链表的第一个公共结点#

/**
 * struct ListNode {
 *  int val;
 *  struct ListNode *next;
 * };
 */

/**
 *
 * @param pHead1 ListNode类
 * @param pHead2 ListNode类
 * @return ListNode类
 */
struct ListNode* FindFirstCommonNode(struct ListNode* pHead1,
                                     struct ListNode* pHead2 ) {
    // write code here

    struct ListNode* pHead1temp = pHead1;
    struct ListNode* pHead2temp = pHead2;

    while (NULL != pHead1temp) {
        pHead2temp = pHead2;  //snowshuang :  开始这里忘记每次都要从头开始遍历忘记加了导致运行不符合预期，如果用for循环应该不会出现这个问题，因为for循环里面赋初值。
        while (NULL != pHead2temp) {
            if (pHead1temp == pHead2temp) {
                return pHead1temp;
            }
            printf("pHead2temp->val = %d, pHead1temp->val = %d\r\n", pHead2temp->val, pHead1temp->val);
            pHead2temp = pHead2temp->next;

        }
        //printf("pHead1temp->val = %d\r\n", pHead1temp->val);
        pHead1temp = pHead1temp->next;
    }

    return NULL;

}