16. 3Sum Closest

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).

public class Solution {
public int threeSumClosest(int[] nums, int target) {
int l = nums.length;
if (l < 3) return Integer.MAX_VALUE;
Arrays.sort(nums);
int result = nums[0] + nums[1] + nums[l-1];
for (int i = 0; i < l-2; i++) {
if (i > 0 && nums[i] == nums[i-1]) continue;
if(nums[i] > target && target >= 0){
if (Math.abs(nums[i]+nums[i+1]+nums[i+2]-target) < Math.abs(result-target)) {
result=nums[i]+nums[i+1]+nums[i+2];
}
return result;
}
for (int j = i+1,k = l-1; j < k; ) {
if (nums[i]+nums[j]+nums[k] == target) {
return target;
}
if (Math.abs(nums[i]+nums[j]+nums[k]-target) < Math.abs(result-target)) {
result=nums[i]+nums[j]+nums[k];
}
if(nums[i]+nums[j]+nums[k] > target){
while(j < k && nums[k-1] == nums[k]){
k--;
}
k--;
}
else {
while(j < k && nums[j+1] == nums[j]){
j++;
}
j++;
}

}
}
return result;
}
}