16. 3Sum Closest

public class Solution {
    public int threeSumClosest(int[] nums, int target) {
       if(nums.length< 3 || nums == null ){
           return -1;
       }
        Arrays.sort(nums);
        int ans = nums[0] + nums[1] + nums[2];
        for(int i = 0; i< nums.length-2 ; i++){ 
            int left = i+1;
            int right = nums.length-1;
            while(left< right){
                int sum = nums[i] + nums[left] + nums[right];
                if(Math.abs(target-sum) < Math.abs(target - ans)){
                    ans = sum;
                }
                if(target <= sum){
                    right--;
                }else{
                    left++;
                }
            }
        }
       
        return ans;
    }
}