LintCode Two Sum Closest

description:

Given an array nums of n integers, find two integers in nums such that the sum is closest to a given number, target.

Return the difference between the sum of the two integers and the target.

Example

Given array nums = [-1, 2, 1, -4], and target = 4.

The minimum difference is 1. (4 - (2 + 1) = 1).

Note:

Two sum and those follow up we can solve them with HashMap and Two Pointer. So we must to identity which one is the best solution to your question.

public class Solution {
/**
* @param nums an integer array
* @param target an integer
* @return the difference between the sum and the target
*/
public int twoSumClosest(int[] nums, int target) {
// Write your code here
if (nums == null || nums.length < 2) {
return -1;
}
Arrays.sort(nums);
int left = 0;
int right = nums.length - 1;
int diff = Integer.MAX_VALUE;
while (left < right) {
if (target > nums[right] + nums[left]) {
diff = Math.min(diff, target - nums[right] - nums[left]);
left++;
} else {
diff = Math.min(diff, nums[right] + nums[left] - target);
right--;
}
}
return diff;
}
}