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).
思路：
这道题跟[leetcode]3Sum并没有太大差别，甚至比更简单，因为并不需要再关心重复数组了，只需要维护一个最小值即可。
代码如下：
public class Solution {
public int threeSumClosest(int[] num, int target) {
int length = num.length;
int min = Integer.MAX_VALUE;
int result = 0;
Arrays.sort(num);
for(int i = 0; i < length - 2;i++){
int begin = i + 1;
int end = length - 1;
while(begin < end){
if(Math.abs(num[i] + num[begin] + num[end] - target) < min){
min = Math.abs(num[i] + num[begin] + num[end] - target);
result = num[i] + num[begin] + num[end];
}
if(num[i] + num[begin] + num[end] > target) end--;
else if(num[i] + num[begin] + num[end] < target) begin++;
else return target;
}
}
return result;
}
}
还是要记得排序，求和问题中，排序似乎是很有效的。
[leetcode]3Sum Closest,布布扣,bubuko.com
原文地址：http://www.cnblogs.com/huntfor/p/3841679.html
