Slip 10 - B) Write a Python class to find validity of a string of parentheses, '(', ')', '{', '}', '[' ']’. These brackets must be close in the correct order. for example "()" and "()[]{}" are valid but "[)", "({[)]" and "{{{" are invalid.

Solution:

class py_solution:
   def is_valid_parenthese(self, str1):
        stack, pchar = [], {"(": ")", "{": "}", "[": "]"}
        for parenthese in str1:
            if parenthese in pchar:
                stack.append(parenthese)
            elif len(stack) == 0 or pchar[stack.pop()] != parenthese:
                return False
        return len(stack) == 0
print(py_solution().is_valid_parenthese("(){}[]"))
print(py_solution().is_valid_parenthese("()[{)}"))
print(py_solution().is_valid_parenthese("()"))

Output: