LeeCode: 3Sum Closest

跟3sum题差不多，可以refer那题

C++：

class Solution {
 public:
     int threeSumClosest(vector<int> &num, int target) {
         // Start typing your C/C++ solution below
         // DO NOT write int main() function
         int maxgap = INT_MAX;
         int maxclose;
         sort(num.begin(), num.end());
         for (int i = 0; i < num.size()-2; i++) {
             int beg = i+1;
             int end = num.size()-1;
             while (beg < end) {
                 int sum = num[i] + num[beg] + num[end];
                 if (sum == target) return target;
                 if (abs(sum - target) < maxgap) {
                     maxgap = abs(sum - target);
                     maxclose = sum;
                 }
                 if (sum < target) beg++;
                 else end--;
             }
         }
         return maxclose;
     }
 };

java：

public class Solution {
    public int threeSumClosest(int[] nums, int target) {
        Arrays.sort(nums);
        int minDis = Integer.MAX_VALUE;
        int ans = nums[0];
        for (int i = 0; i < nums.length; i++)
        {
            if (i > 0 && nums[i] == nums[i-1]) continue;
            int left = i + 1;
            int right = nums.length - 1;
            while (left < right)
            {
                if (left > i + 1 && nums[left] == nums[left-1])
                {
                    left++;
                    continue;
                }
                int sum = nums[i] + nums[left] + nums[right];
                if (Math.abs(target-sum) < minDis) {
                    ans = sum;
                    minDis = Math.abs(target - sum);
                }
                if (sum == target) break;
                else if (sum > target) right--;
                else left++;
            }
        }
        return ans;
    }
}