题解 | #链表中环的入口结点#
链表中环的入口结点
https://www.nowcoder.com/practice/253d2c59ec3e4bc68da16833f79a38e4
/**
* struct ListNode {
* int val;
* struct ListNode *next;
* };
*/
/**
* 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
*
*
* @param pHead ListNode类
* @return ListNode类
*/
struct ListNode* EntryNodeOfLoop(struct ListNode* pHead ) {
// write code here
if(pHead->next == NULL) return NULL;
struct ListNode* run = pHead;
struct ListNode* man = pHead;
while(run && man){
run=run->next->next;
man=man->next;
if(run==man){
break;
}
}
if(run == NULL || man==NULL) return NULL;
if(run == pHead) return pHead;
man = pHead;
while(true){
man = man->next;
run = run->next;
if(man == run){
return man;
}
}
}
查看22道真题和解析