LeetCode/Valid Parentheses at master · leoleo30539/LeetCode · GitHub

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class Solution(object):
    def isValid(self, s):
        """
        :type s: str
        :rtype: bool
        """
        stack = []
        for i in s:
            if(i == '('):
                stack.append(1)
            if(i == ')'):
                if not stack:
                    return False
                elif(stack[len(stack)-1] != 1):
                    return False
                else:
                    stack.pop()
            if(i == '{'):
                stack.append(2)
            if(i == '}'):
                if not stack:
                    return False
                elif(stack[len(stack)-1] != 2):
                    return False
                else:
                    stack.pop()
            if(i == '['):
                stack.append(3)
            if(i == ']'):
                if not stack:
                    return False
                elif(stack[len(stack)-1] != 3):
                    return False
                else:
                    stack.pop()
        if not stack:
            return True
        else:
            return False