Day 7

Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

An input string is valid if:

Open brackets must be closed by the same type of brackets.
Open brackets must be closed in the correct order.
Every close bracket has a corresponding open bracket of the same type.

CODE:
        # Stack to store opening brackets
        stack = []
        # Mapping of closing brackets to their corresponding opening brackets
        bracket_map = {')': '(', '}': '{', ']': '['}
        
        # Iterate through each character in the string
        for char in s:
            if char in bracket_map:
                # Pop the top element of the stack if it matches the corresponding opening bracket
                top_element = stack.pop() if stack else '#'
                if bracket_map[char] != top_element:
                    return False
            else:
                # Push opening brackets onto the stack
                stack.append(char)
        
        # If the stack is empty, all brackets were matched correctly
        return not stack