# 30 lines c# code win over 100%

• Hi all,
This is my first post. So if I write anything wrong please let me know.
Here is my code which used basic 3sum and 3sum closet solution. Very easy to understand if you passed 3sum problems.

``````public class Solution
{
public IList<IList<int>> FourSum(int[] nums, int target)
{
List<IList<int>> result = new List<IList<int>>();
if (nums.Length < 4) return result;
int sum = 0,len = nums.Length;
Array.Sort(nums);
for (int i = 0; i < len - 3; i++)
{
for (int j = i + 1; j < len - 2; j++)
{
int lo = j + 1; int hi = len - 1;
while (lo < hi)
{
sum = nums[lo] + nums[hi] + nums[i] + nums[j];
if (sum == target)
{
result.Add(new List<int> { nums[i], nums[j], nums[lo], nums[hi] });
while (i < len - 3 && nums[i] == nums[i + 1]) i++;
while (j < len - 2 && nums[j] == nums[j + 1]) j++;
while (lo < hi && nums[lo] == nums[lo + 1]) lo++;
while (lo < hi && nums[hi] == nums[hi - 1]) hi--;
lo++;
hi--;
}
else if (target > sum) lo++;
else hi--;
}
}
}
return result;
}
}
``````

Looks like your connection to LeetCode Discuss was lost, please wait while we try to reconnect.