20

1 files changed, 47 insertions, 0 deletions

diff --git a/20/main.py b/20/main.py
new file mode 100644
index 0000000..b3c5136
--- /dev/null
+++ b/20/main.py
@@ -0,0 +1,47 @@
+#!/usr/bin/env python
+
+
+class Solution:
+    def isValid(self, s: str) -> bool:
+        stack = []
+        for char in s:
+            if char == "(":
+                stack.append("(")
+            elif char == "[":
+                stack.append("[")
+            elif char == "{":
+                stack.append("{")
+            elif char == ")":
+                if len(stack) == 0:
+                    return False
+                if stack[-1] == "(":
+                    stack.pop()
+                else:
+                    return False
+            elif char == "]":
+                if len(stack) == 0:
+                    return False
+                if stack[-1] == "[":
+                    stack.pop()
+                else:
+                    return False
+            elif char == "}":
+                if len(stack) == 0:
+                    return False
+                if stack[-1] == "{":
+                    stack.pop()
+                else:
+                    return False
+
+        if len(stack) != 0:
+            return False
+
+        return True
+
+
+def main() -> None:
+    solution = Solution()
+
+
+if __name__ == "__main__":
+    main()