Day i do not know

77. Combinations/Solution.cs

@@ -0,0 +1,26 @@
+namespace _77._Combinations;
+
+public class Solution
+{
+    public IList<IList<int>> Combine(int n, int k)
+    {
+        List<IList<int>> res = new List<IList<int>>();
+        Recursion(res, new List<int>(), 1, n, k);
+        return res;
+    }
+
+    private void Recursion(List<IList<int>> result, List<int> cur, int minNum, int maxNum, int count)
+    {
+        if (cur.Count == count)
+        {
+            result.Add(cur.ToList());
+            return;
+        }
+        for (int toAdd = minNum; toAdd <= maxNum; toAdd++)
+        {
+            cur.Add(toAdd);
+            Recursion(result, cur, toAdd + 1, maxNum, count);
+            cur.RemoveAt(cur.Count-1);
+        }
+    }
+}