Add code with set

Author: colorbox

141/with_set.cpp

@@ -0,0 +1,16 @@
+// チェック済みのノードを記憶しておく解法のコード
+class Solution {
+public:
+    bool hasCycle(ListNode *head) {
+        set<ListNode*> reached;
+        ListNode* current = head;
+        while (current) {
+            if (reached.count(current)) {
+                return true;
+            }
+            reached.insert(current);
+            current = current->next;
+        }
+        return false;
+    }
+};