diff --git "a/leetcode3/\355\231\251\354\235\200\354\247\200/219. Contains Duplicate II.js" "b/leetcode3/\355\231\251\354\235\200\354\247\200/219. Contains Duplicate II.js"
new file mode 100644
index 00000000..53ac972d
--- /dev/null
+++ "b/leetcode3/\355\231\251\354\235\200\354\247\200/219. Contains Duplicate II.js"	
@@ -0,0 +1,14 @@
+/**
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {boolean}
+ */
+var containsNearbyDuplicate = function (nums, k) {
+  const set = new Set();
+  for (let i = 0; i < nums.length; i++) {
+    if (i > k) set.delete(nums[i - k - 1]);
+    if (set.has(nums[i])) return true;
+    set.add(nums[i]);
+  }
+  return false;
+};