3Sums.cpp

class Solution {
public:
    vector<vector<int>> threeSum(vector<int>& nums) {
        int len = nums.size();
        vector<vector<int>> finalResult;
        std::sort(nums.begin(), nums.end());
        if(len <= 2)
            return finalResult;
        
        for(int i = 0; i < len - 2; i++)
        {
            int a = nums[i];
            if(a > 0)
                break;
            if(i > 0 && a == nums[i-1])
                continue;
            
            for(int j = i + 1, k = len - 1; j < k;)
            {
                int b = nums[j];
                int c = nums[k];
                int value = a + b + c;
                if(value == 0)
                {
                    finalResult.push_back({a,b,c});
                    while(j<len - 1 && b == nums[++j]);
                    while(c> 0 && c == nums[--k]);
                }
                else if(value > 0)
                    k--;
                else
                    j++;
            } 
        }
        return finalResult;
    }
};