16 - 3Sum Closest

 JAVA

• class Solution {
      public int threeSumClosest(int[] nums, int target) {
          Arrays.sort(nums);
          int ans = 1 << 30;
          int n = nums.length;
          for (int i = 0; i < n; ++i) {
              int j = i + 1, k = n - 1;
              while (j < k) {
                  int t = nums[i] + nums[j] + nums[k];
                  if (t == target) {
                      return t;
                  }
                  if (Math.abs(t - target) < Math.abs(ans - target)) {
                      ans = t;
                  }
                  if (t > target) {
                      --k;
                  } else {
                      ++j;
                  }
              }
          }
          return ans;
      }
  }

C++

• class Solution {
  public:
      int threeSumClosest(vector<int>& nums, int target) {
          sort(nums.begin(), nums.end());
          int ans = 1 << 30;
          int n = nums.size();
          for (int i = 0; i < n; ++i) {
              int j = i + 1, k = n - 1;
              while (j < k) {
                  int t = nums[i] + nums[j] + nums[k];
                  if (t == target) return t;
                  if (abs(t - target) < abs(ans - target)) ans = t;
                  if (t > target)
                      --k;
                  else
                      ++j;
              }
          }
          return ans;
      }
  };