README.md

2574. Left and Right Sum Differences

Given a 0-indexed integer array nums, find a 0-indexed integer array answer where:

• answer.length == nums.length.
• answer[i] = |leftSum[i] - rightSum[i]|.

Where:

• leftSum[i] is the sum of elements to the left of the index i in the array nums. If there is no such element, leftSum[i] = 0.
• rightSum[i] is the sum of elements to the right of the index i in the array nums. If there is no such element, rightSum[i] = 0.

Return the array answer.

Example 1:

Input: nums = [10,4,8,3]
Output: [15,1,11,22]
Explanation: The array leftSum is [0,10,14,22] and the array rightSum is [15,11,3,0].
The array answer is [|0 - 15|,|10 - 11|,|14 - 3|,|22 - 0|] = [15,1,11,22].

Example 2:

Input: nums = [1]
Output: [0]
Explanation: The array leftSum is [0] and the array rightSum is [0].
The array answer is [|0 - 0|] = [0].

Constraints:

• 1 <= nums.length <= 1000
• 1 <= nums[i] <= 105

Solutions (Rust)

1. Solution

impl Solution {
    pub fn left_right_difference(nums: Vec<i32>) -> Vec<i32> {
        let n = nums.len();
        let mut left_sum = vec![0; n];
        let mut right_sum = vec![0; n];

        for i in 1..n {
            left_sum[i] = left_sum[i - 1] + nums[i - 1];
            right_sum[n - 1 - i] = right_sum[n - i] + nums[n - i];
        }

        (0..n).map(|i| (left_sum[i] - right_sum[i]).abs()).collect()
    }
}