16.最接近的三数之和-双指针

class Solution {
    
    
public:
    int threeSumClosest(vector<int>& nums, int target) {
    
    
        int sum, better_sum = 100000;
        int n = nums.size();
        sort(nums.begin(), nums.end());
        for(int i = 0; i < n - 2; i++){
    
    
            if(i > 0 && nums[i] == nums[i - 1]) continue;
            int l_point = i + 1, r_point = n - 1;
            while(l_point < r_point){
    
    
                int sum = nums[i] + nums[l_point] + nums[r_point];
                if(abs(sum - target) < abs(better_sum - target))
                    better_sum = sum;
                if(sum == target){
    
    
                    return target;
                }
                else if(sum < target){
    
    
                    l_point++;
                }
                else{
    
    
                    r_point--;
                }
            }
        }
        return better_sum;
    }
};

Accepted
131/131 cases passed (4 ms)
Your runtime beats 97.99 % of cpp submissions
Your memory usage beats 85.98 % of cpp submissions (9.5 MB)