---
tags: data_structure_python
---

# Valid Parentheses <img src="https://img.shields.io/badge/-easy-brightgreen">

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

An input string is valid if:

1. Open brackets must be closed by the same type of brackets.
2. Open brackets must be closed in the correct order.

Note that an empty string is also considered valid.

<ins>**Example 1:**</ins>

>Input: "()"
>Output: true

<ins>**Example 2:**</ins>

>Input: "()[]{}"
>Output: true

<ins>**Example 3:**</ins>

>Input: "(]"
>Output: false

<ins>**Example 4:**</ins>

>Input: "([)]"
>Output: false

<ins>**Example 5:**</ins>

>Input: "{[]}"
>Output: true

## Solution

class Solution:
    def isValid(self, s: str) -> bool:
        Map = {'}': '{', ']': '[', ')': '('}
        stack = []
        
        for char in s:
            
            if char not in Map:
                stack.append(char)
            else:
                if len(stack) == 0 or stack[-1] != Map[char]: 
                    return False
                
                stack.pop(-1)
            
        return len(stack) == 0