LeetCode/problems/find-pivot-index.rs

use std::convert::TryInto;

impl Solution {    
    pub fn pivot_index(nums: Vec<i32>) -> i32 {
        let mut from_left: i32 = 0;
        let mut from_right: i32 = nums.iter().sum();
        
        for (i, e) in nums.iter().enumerate() {
            from_right -= e;
            
            if from_left == from_right {
                return i.try_into().unwrap();
            }
            
            from_left += e;
        }
        
        -1
    }
}