# Leetcode 16. 3Sum Closest

[medium]

Given an array `nums`

of *n* integers and an integer `target`

, find three integers in `nums`

such that the sum is closest to `target`

. Return the sum of the three integers. You may assume that each input would have exactly one solution.

**Example 1:**

**Input:** nums = [-1,2,1,-4], target = 1

**Output:** 2

**Explanation:** The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).

**Constraints:**

`3 <= nums.length <= 10^3`

`-10^3 <= nums[i] <= 10^3`

`-10^4 <= target <= 10^4`

[Java]

- TC(O²)
- track current min different from 3-SUM and target
- use Math.abs(sum — target) < Math.abs(result — target)
- use Arrays.sort first, so the array sort from small to large; use two pointer (start, end) to find the minium result