标签:style blog class c code java
题意: 给出单链表, 判断是否存在环.
方法就是大步小步...
附上代码:
1 /**
2 * Definition for singly-linked list.
3 * struct ListNode {
4 * int val;
5 * ListNode *next;
6 * ListNode(int x) : val(x), next(NULL) {}
7 * };
8 */
9 class Solution {
10 public:
11 bool hasCycle(ListNode *head) {
12 if (head == NULL or head->next == NULL) {
13 return false;
14 }
15 ListNode *fast = head, *slow = head;
16 while (fast != NULL and fast->next != NULL) {
17 fast = fast->next;
18 if (fast == slow) {
19 return true;
20 }
21 fast = fast->next;
22 if (fast == slow) {
23 return true;
24 }
25 slow = slow->next;
26 }
27 return false;
28 }
29 };
LeetCode -- Linked List Cycle,布布扣,bubuko.com
标签:style blog class c code java
原文地址:http://www.cnblogs.com/Stomach-ache/p/3731125.html