16. 最接近的三数之和

class Solution {
public:
    int threeSumClosest(vector<int>& nums, int target) {
        int error = INT_MAX, a, b, c, len = nums.size(), res, sum, temp;
        sort(nums.begin(), nums.end());
        for(a = 0; a <len; a++)
        {
            if(a>0&&nums[a]==nums[a-1])
                continue;
            sum = target-nums[a];
            b = a+1;
            c = len-1;
            while(b<c)
            {
                temp = nums[b]+nums[c];
                if(sum==temp)
                {
                    return target;
                }
                if(abs(sum-temp)<error)
                {
                     error = abs(sum-temp);
                     res = nums[a]+nums[b]+nums[c];
                }
                if(temp<sum)
                {
                    b++;
                }
                else
                {
                    c--;
                }
                
                   
            }
        }
        return res;

    }
};