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).
1 public class Solution { 2 //len-3 len-2 len-1 3 public int threeSumClosest(int[] num, int target) { 4 int len = num.length; 5 int min = Integer.MAX_VALUE; 6 int res = 0; 7 if(len<3) return 0; 8 Arrays.sort(num); 9 for(int i=0;i<=len-3;i++){ 10 int start = i+1; 11 int end = len-1; 12 while(start<end){ 13 int sum = num[i]+num[start]+num[end]; 14 if(sum==target){ 15 return sum; 16 } 17 else if(sum<target){ 18 if(min>Math.abs(sum-target)){ 19 min = Math.abs(sum-target); 20 res = sum; 21 } 22 start++; 23 } 24 else{ 25 if(min>Math.abs(sum-target)){ 26 min = Math.abs(sum-target); 27 res = sum; 28 } 29 end--; 30 } 31 } 32 while(i<len-3 && num[i]==num[i+1]){ 33 i++; 34 } 35 } 36 return res; 37 } 38 }
原文：http://www.cnblogs.com/krunning/p/3555137.html
