141. Linked List Cycle
阿新 • • 發佈:2017-07-24
nod list struct xtra clas {} amp can for
Given a linked list, determine if it has a cycle in it.
Follow up:
Can you solve it without using extra space?
一個+1 一個+2 看看能不能相遇。註意代碼不要寫亂了...以後盡量用p1 p2 這種變量名,不要用p ,q讓人看著眼花繚亂
/** * 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) { ListNode * p1 = head; ListNode * p2 = head; while (p2 != nullptr && p2->next!=nullptr) { p1 = p1->next; p2 = p2->next->next; if (p1 == p2) {return true; } } return false; } };
141. Linked List Cycle