【LeetCode】016.3Sum Closest

<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">题目：</span>

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).

解答：
双指针问题，将数组排序后，依次遍历，当前值往后的部分的首、尾各放一个指针，进行双指针遍历，找到最接近的值

代码：

public class Solution {
public int threeSumClosest(int[] nums, int target) {
Arrays.sort(nums);
int ret = nums[0] + nums[1] + nums[nums.length-1];
for(int i=0;i<nums.length-2;i++){
int j=i+1;
int k=nums.length-1;
int result;
while(j<k){
result = nums[i]+nums[j]+nums[k];
if(result == target)
return result;
if(Math.abs(result-target) < Math.abs(ret-target))
ret = result;
if(result < target)
j++;
else
k--;
}
}
return ret;
}
}