Add #0020 Valid Parentheses

Author: dgper13

#0020 Valid Parentheses.py

@@ -0,0 +1,32 @@
+class Solution:
+    def isValid(self, s: str) -> bool:
+        """
+        Determine if the input string s has valid parentheses.
+
+        Args:
+        s (str): Input string consisting of parentheses '(', ')', '[', ']', '{', '}'
+
+        Returns:
+        bool: True if the parentheses are valid, False otherwise.
+        """
+        # Mapping of opening to closing parentheses
+        entries = {
+            "(": ")",
+            "[": "]",
+            "{": "}"
+        }
+        
+        stack = []
+
+        for c in s:
+            if c in entries:
+                # Push corresponding closing bracket onto the stack
+                stack.append(entries[c])
+            else:
+                # If stack is empty or the top of stack doesn't match current character
+                if not stack or stack.pop() != c:
+                    return False
+        
+        # Stack should be empty if all opening brackets had matching closing brackets
+        return not stack
+