LeetCode 16. 3Sum Closest

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).

题目大意:给定一个整型数组,在数组中找xyz,使x+y+z最接近target,返回最接近的x+y+z的值~

分析:对nums排序,先确定第一个数为nums[i], 使begin = i + 1,end = n – 1,如果当前sum == target,就令begin++,end–,指针分别向前向后移动一个,如果sum比较大,就令end往前一个;如果sum比较小,就令begin往后一个~每次根据sum更新result的值,result设置为long型,避免一开始是INT最大值、加了负数后溢出~