Problem Overview

Given an array of integers nums and an integer target, return all pairs of numbers where one of the four arithmetic operations (+, -, *, /) produces exactly the target value.

For each valid pair (a, b) where a op b = target, return the expression as a string in the format "a{op}b" (e.g., "2+4", "3*2").

This problem tests your ability to enumerate all valid combinations while handling edge cases like division by zero, order-dependent operations, and duplicate values.

Example

` nums = [2, 4, 6, 3] target = 6

result = findPairs(nums, target)

Returns ["2+4", "4+2", "23", "32"]

Explanation:

2 + 4 = 6

4 + 2 = 6

2 * 3 = 6

3 * 2 = 6

`

Requirements

• Consider all four operations: addition (+), subtraction (-), multiplication (*), division (/)

• Order matters: "2+4" and "4+2" are different pairs

• For division, only include pairs where:

• Division is exact (no remainder)

• If the same value appears multiple times, each occurrence is treated as distinct

• Return each unique expression string only once, even if multiple index pairs produce it

• Should we handle floating-point division or only integer division?

• What if the target is 0? Can we have 0 in the array?

• Should we validate that nums has at least 2 elements?

• Are there performance requirements for large arrays?