LeetCode 16

原题:

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).

题意：给定一个数组和一个target，求3个数和最接近target的一组

代码和思路：

class Solution {    public int threeSumClosest(int[] nums, int target) {        Arrays.sort(nums);        int result = nums[0] + nums[1] + nums[nums.length - 1];        for(int i=0;i<nums.length-2;i++){            int lo = i+1, hi = nums.length-1;            while(lo<hi){                int sum = nums[i] +nums[lo] + nums[hi];                if(sum>target) hi--;                else           lo++;                //因为是求相近，比较绝对值的差                if(Math.abs(sum-target)<Math.abs(result-target))  result = sum;                          }        }        return result;    }}