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).
给定一个序列，找出其中三个数，使其和与target最为接近，返回三个数的和。
public class Solution {
public int threeSumClosest(int[] nums, int target) {
List<Integer> result = new ArrayList<Integer>();
if (nums == null || nums.length < 3) return 0;
Arrays.sort(nums);
int number = nums[0] + nums[1] + nums[2];
int closest = Math.abs(number - target);
for (int i = 0; i < nums.length - 2; i++) {
if (i > 0 && nums[i] == nums[i-1]) continue;
int left = i + 1;
int right = nums.length - 1;
while (left < right) {
int tmp = nums[i] + nums[left] + nums[right];
if (Math.abs(tmp - target) < closest) {
number = tmp;
closest = Math.abs(tmp - target);
}
if (tmp > target) right--;
if (tmp < target) left++;
if (tmp == target) return tmp;
}
}
return number;
}
}