Leetcode 16. 3Sum Closest (Medium) (java)

Leetcode 16. 3Sum Closest (Medium) (java)

Tag: Array, Two Pointers

Difficulty: Medium

/*

16. 3Sum Closest (Medium)

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) {
if (nums.length < 3) {
return 0;
}
Arrays.sort(nums);
int res = nums[0] + nums[1] + nums[2];
for (int i = 0; i < nums.length - 2; i++) {
int j = i + 1, k = nums.length - 1;
while (j < k) {
int _sum = nums[i] + nums[j] + nums[k];
if (_sum == target) {
return _sum;
}
else if (Math.abs(_sum - target) < Math.abs(res - target)) {
res = _sum;
}
else if (_sum > target) {
k--;
}
else {
j++;
}
}
}
return res;
}
}