【easy】141. Linked List Cycle
阿新 • • 發佈:2018-02-13
next sin span for 指針 slow nod fast 有環
非常簡單的題:判斷鏈表有沒有環(用快慢指針)
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
bool hasCycle(ListNode *head) {
if (head == NULL)
return false;
ListNode *fast = head;
ListNode *slow = head;
while (fast->next != NULL){
fast = fast->next->next;
slow = slow->next;
if (fast == NULL)
return false;
if (fast == slow)
return true;
}
return false;
}
};
【easy】141. Linked List Cycle