created solution for problem58

Author: dampdigits

problem58/Solution.py

@@ -0,0 +1,25 @@
+class Solution:
+    def combinationSum3(self, k: int, n: int) -> List[List[int]]:
+        ans = []
+        combo = []
+        
+        def backtrack(size, sum):
+            if size == k:
+                if sum == n:
+                    ans.append(combo.copy())
+                    return True
+                return False
+
+            strt = 1 if not combo else combo[-1]+1
+            
+            for i in range(strt, 10):
+                combo.append(i)
+                sum += i
+                found = backtrack(size+1, sum)
+                sum -= i
+                combo.pop(-1)
+                if found: break
+            return False
+
+        backtrack(0, 0)
+        return ans