3Sum Closest

题目描述：

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.

确定一个，然后用两指针法，代码如下：

public class Solution {
    public int threeSumClosest(int[] nums, int target) {
        Arrays.sort(nums);
        int result=0;
        int min=Integer.MAX_VALUE;
        for (int i = 0; i < nums.length; i++) {
            int low=i+1,high=nums.length-1;
            while(low<high){
                int n=Math.abs(target-nums[i]-nums[low]-nums[high]);
                if(n<min){
                    min=n;
                    result=nums[i]+nums[low]+nums[high];
                }
                //System.out.println("min:"+min);
                if(target-nums[i]-nums[low]-nums[high]>0){
                    low++;
                }else{
                    high--;
                }
            }
        }
        return result;
    }
}