# Reach a Target Using Each Number At Most Once You are given an array of integers `nums` and an integer `target`. Decide whether you can build an arithmetic expression that evaluates to exactly `target`, under the following rules: - Each **element** of `nums` may be used **at most once**. Elements with equal values count as separate elements. You do not have to use every element, but you must use at least one. - The numbers you pick may be arranged in any order and combined with the binary operators `+`, `-`, `*`, `/`, with any parenthesization. - Division is exact mathematical (rational) division: intermediate results may be non-integer fractions. Division by zero is not allowed at any step. - No unary minus, and no concatenating digits of different numbers (e.g. you may not glue `1` and `2` into `12`). - An expression consisting of a single picked number (no operators) is allowed, so if some element already equals `target`, the answer is `true`. Return `true` if `target` is reachable, otherwise `false`. Equality must be exact (rational arithmetic), not approximate floating-point equality. ## Examples **Example 1** ``` Input: nums = [1, 2, 3, 4], target = 24 Output: true ``` Pick `2`, `3`, `4` (leaving `1` unused): `2 * 3 * 4 = 24`. **Example 2** ``` Input: nums = [3, 3, 8, 8], target = 24 Output: true ``` `8 / (3 - 8 / 3) = 8 / (1/3) = 24`. Note the intermediate values are fractions — exact rational arithmetic matters. **Example 3** ``` Input: nums = [2, 5], target = 9 Output: false ``` All reachable values are `2`, `5`, `7`, `-3`, `3`, `10`, `2/5`, `5/2` — none equals `9`. ## Constraints - `1 <= nums.length <= 5` - `0 <= nums[i] <= 100` - `-10^4 <= target <= 10^4`