[Leetcode] 3Sum Cloest

Problem

Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution.

    For example, given array S = {-1 2 1 -4}, and target = 1.

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

Analysis

• Brute force approach
• Enumerate the first, second, third number respectively
• Update the distance compared with the target
• Time: O(n^3)
• Space: O(1)

Code