Create 141.cpp

LeetCode-CN/141.cpp

@@ -0,0 +1,14 @@
+class Solution {
+public:
+	bool hasCycle(ListNode *head) {
+		if (head == nullptr || head->next == nullptr) return false;
+		ListNode* p = head;
+		ListNode* q = head->next->next;
+		while (p != q && q && q->next)
+		{
+			p = p->next;
+			q = q->next->next;
+		}
+		return (p == q);
+	}
+};