Merge pull request #1416 from imevanc/Create-724-Find-Pivot-Index.js

Create: 724-Find-Pivot-Index.js

Author: Ahmad-A0

javascript/724-Find-Pivot-Index.js

@@ -0,0 +1,21 @@
+/**
+ * https://leetcode.com/problems/find-pivot-index/
+ * @param {number[]} nums
+ * @return {number}
+ */
+var pivotIndex = function (nums) {
+    const totalSum = nums.reduce((sum, el) => {
+        sum += el;
+        return sum;
+    }, 0);
+    let pos = 0;
+    let leftSum = 0;
+    while (pos <= nums.length - 1) {
+        if (leftSum === totalSum - nums[pos] - leftSum) {
+            return pos;
+        }
+        leftSum += nums[pos];
+        pos++;
+    }
+    return -1;
+};