Time: 142 ms (36.19%), Space: 59.6 MB (87.09%) - LeetHub

Author: hogan-tech

0077-combinations/0077-combinations.py

@@ -0,0 +1,19 @@
+# time complexity: O(n!)
+# space complexity: O(n)
+class Solution:
+    def combine(self, n: int, k: int) -> List[List[int]]:
+        result = []
+
+        def backtrack(start, comb):
+            if len(comb) == k:
+                result.append(list(comb))
+                return
+            
+            for i in range(start, n + 1):
+                comb.append(i)
+                backtrack(i + 1, comb)
+                comb.pop()
+            
+
+        backtrack(1, [])
+        return result