Create 141. Linked List Cycle

Author: jyoung2419

leetcode3/정진영/141. Linked List Cycle

@@ -0,0 +1,26 @@
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+
+/**
+ * @param {ListNode} head
+ * @return {boolean}
+ */
+var hasCycle = function(head) {
+    let curr = head;
+    let visited = new Set();
+
+    while (curr !== null){
+        if (visited.has(curr)){
+            return true;
+        }
+        visited.add(curr);
+        curr = curr.next;
+    }
+
+    return false;
+};