# 16 3Sum Closest – Medium

### Problem:

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).
``````

### Thoughts:

This is almost the same problem with 3Sum. The only difference is the checking condition. Instead of a + b + c = 0, check if (a + b + c – target) is min.

### Solutions:

``````public class Solution {
public int threeSumClosest(int[] nums, int target) {
if (nums.length == 0){
return 0;
}
Arrays.sort(nums);
int min = Integer.MAX_VALUE;
int closed = 0;
for (int i = 0; i < nums.length; i ++){
if (i == 0 || nums[i] != nums[i-1]){
int start = i + 1;
int end = nums.length - 1;
while (start < end){
int sum = nums[i] + nums[start] + nums[end];
if (Math.abs(sum - target) < min){
min = Math.abs(sum - target);
closed = sum;
}
if (sum < target){
start ++; }
else{ // >= target
end --;
}//if
}//while
}//if
}//for
return closed;
}
}
``````