最接近的三数之和

 1 public class T16 {
 2     public int threeSumClosest(int[] nums, int target) {
 3         if (nums == null || nums.length < 3) {
 4             return 0;
 5         }
 6         Arrays.sort(nums);
 7         int res = nums[0] + nums[1] + nums[2];
 8         for (int i = 0; i < nums.length - 2; i++) {
 9             int l = i + 1;
10             int r = nums.length - 1;
11             while (l < r) {
12                 int sum = nums[i] + nums[l] + nums[r];
13                 if (Math.abs(sum - target) < Math.abs(res - target)) {
14                     res = sum;
15                 }
16                 if (sum > target) {
17                     r--;
18                 } else if (sum < target) {
19                     l++;
20                 } else {
21                     return sum;
22                 }
23             }
24         }
25         return res;
26     }
27 }