missing-number solution

Author: lhc0506

missing-number/lhc0506.js

@@ -0,0 +1,18 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var missingNumber = function(nums) {
+  const n = nums.length;
+  const array = new Array(n).fill(false);
+
+  for (let i = 0; i < n; i++) {
+      array[nums[i]] = true;
+  }
+
+  const index = array.findIndex(item => item === false);
+  return index === -1 ? n : index;
+};
+
+// 시간 복잡도: O(n)
+// 공간 복잡도: O(n)