leetcode 4sum

vector<vector<int>> fourSum(vector<int>& nums, int target) {
	vector< vector<int> > result;
	sort(nums.begin(), nums.end());
	for (int i = 0; i < nums.size(); ++i)
	{
		for (int j = i + 1; j < nums.size(); ++j)
		{
			int temp = target - nums[i] - nums[j], m = j + 1, n = nums.size() - 1;
			while (m < n)
			{
				if (nums[m] + nums
 < temp)
					++m;
				else if (nums[m] + nums
 > temp)
					--n;
				else
				{
					result.push_back({ nums[i], nums[j], nums[m], nums
 });
					++m;
					while (m < n && nums[m - 1] == nums[m]) ++m;
					--n;
					while (m < n && nums[n + 1] == nums
) --n;
				}
			}
			while (j + 1 < nums.size() && nums[j + 1] == nums[j]) ++j;
		}
		while (i + 1 < nums.size() && nums[i + 1] == nums[i]) ++i;
	}
	return result;
    }

vector<vector<int>> fourSum(vector<int>& nums, int target) {
        if(nums.size() < 4) return {};
	vector< vector<int> > result;
	sort(nums.begin(), nums.end());
	for (int i = 0; i < nums.size() - 3; ++i)
		for (int j = i + 1; j < nums.size() - 2; ++j)
		{
			int temp = target - nums[i] - nums[j], m = j + 1, n = nums.size() - 1;
			while (m < n)
			{
				if (nums[m] + nums
 < temp)
					++m;
				else if (nums[m] + nums
 > temp)
				    --n;
				else
				{
				   vector<int> itemp({ nums[i], nums[j], nums[m], nums
 });
					if (find(result.begin(), result.end(), itemp) == result.end())
						result.push_back({ nums[i], nums[j], nums[m], nums
 });
					++m;
					--n;
				}
			}
		}
	return result;
    }