Two Numbers With Sum Closest to Zero

Question

## Problem

Given an array of integers (positive and negative), find the pair whose sum is closest to zero.

## Example
```
[1, 60, -10, 70, -80, 85] -> (-80, 85) sum 5
```

## Constraints
- 2 ≤ n ≤ 10^5

## Approach
Sort, then two pointers tracking the minimum absolute sum.