Return Absolute Differences of Strictly Left and Right Sums
Company: Google
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: easy
Interview Round: Other
### Problem
For each index i in `nums`, sum entries strictly to its left and strictly to its right, using 0 for an empty side. Return the absolute difference of those two sums for every index in original order.
```cpp
class Solution {
public:
vector<int> leftRightDifference(vector<int>& nums);
};
```
### Examples
**Example 1:**
```text
Input: nums = [2,5,1]
Output: [6,1,7]
Explanation: Left sums are [0,2,7], and right sums are [6,1,0].
```
**Example 2:**
```text
Input: nums = [4,4]
Output: [4,4]
Explanation: Each index has one 4 on its opposite side and an empty other side.
```
### Constraints
- `1 <= nums.length <= 1000`.
- `1 <= nums[i] <= 100000`.
### Clarifying Questions
- Is the current element included in either sum? No.
- What is an empty side's sum? Zero.
- Is the difference signed? No; return its absolute value.
- What order should answers use? The original index order.
```hint Check the boundary
For a one-element array, both side sums are empty.
```
Overview: Return each index’s absolute difference between the sums strictly to its left and right, treating empty sides as zero.