missingnumber

Author: OmPreetham

268-missing-number.js

@@ -0,0 +1,10 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var missingNumber = function(nums) {
+    let n = nums.length;
+    let expectedSum = (n * (n + 1)) / 2;
+    let actualSum = nums.reduce((acc, curr) => acc + curr, 0);
+    return expectedSum - actualSum;
+};