16. 3Sum Closest.cpp

class Solution {
public:
    int threeSumClosest(vector<int>& nums, int target) {
        int n = nums.size();
       
        sort(nums.begin(), nums.end());
        
        
        int resultSum = nums[0] + nums[1] + nums[2];
        int minDiff = INT_MAX;  

        for (int i = 0; i < n - 2; i++) {
           
            if (i > 0 && nums[i] == nums[i - 1]) continue;

            int j = i + 1;
            int k = n - 1;
            while (j < k) {
                int sum = nums[i] + nums[j] + nums[k];

               
                if (sum == target) return target;
                else if (sum < target) j++;   
                else k--;                   

                int diffToTarget = abs(sum - target);
                
                if (diffToTarget < minDiff) {
                    resultSum = sum;
                    minDiff = diffToTarget;
                }
            }
        }
        return resultSum;
    }
};