Find Pivot Index

1class Solution {
2    public int pivotIndex(int[] nums) {
3        int totalSum = 0;
4        int leftSum = 0;
5
6        for (int i = 0; i < nums.length; i++) {
7            totalSum += nums[i];
8        }
9
10        for (int i = 0; i < nums.length; i++) {
11            if (leftSum == totalSum - nums[i] - leftSum) {
12                return i;
13            }
14            leftSum += nums[i];
15        }
16
17        return -1;
18    }
19}