[LeetCode] generate-parentheses

coding_test/leetcode/generate-parentheses/test.py

@@ -0,0 +1,49 @@
+from typing import List
+
+
+class Solution:
+    def generateParenthesis(self, n: int) -> List[str]:
+        res = []
+        stack = []
+
+        def backtrack(opened: int, closed: int):
+            if opened == closed == n:
+                res.append("".join(stack))
+                return
+
+            if opened < n:
+                stack.append("(")
+                backtrack(opened + 1, closed)
+                stack.pop()
+
+            if closed < opened:
+                stack.append(")")
+                backtrack(opened, closed + 1)
+                stack.pop()
+
+        backtrack(0, 0)
+        return res
+
+
+def test():
+    sol = Solution()
+    assert sorted(sol.generateParenthesis(1)) == sorted(
+        [
+            "()",
+        ]
+    )
+    assert sorted(sol.generateParenthesis(2)) == sorted(
+        [
+            "(())",
+            "()()",
+        ]
+    )
+    assert sorted(sol.generateParenthesis(3)) == sorted(
+        [
+            "((()))",
+            "(()())",
+            "(())()",
+            "()(())",
+            "()()()",
+        ]
+    )