Day23_LEETCODE_20. Valid Parentheses.ipynb

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    "class Solution:\n",
    "    def isValid(self, s: str) -> bool:\n",
    "        # The stack to keep track of opening brackets.\n",
    "        stack = []\n",
    "        bracketmap = { ']' : '[' ,  ')': '('  , '}' : '{' }\n",
    "        for i in s:\n",
    "            # For closing brackets\n",
    "            if i in bracketmap:\n",
    "                \n",
    "                # Assigning dummy value of # if stack is empty\n",
    "                topbracket= stack.pop() if stack else '#'  \n",
    "                \n",
    "                # Checking if the opening bracket patterns match\n",
    "                if topbracket != bracketmap[i]:\n",
    "                    return False\n",
    "            \n",
    "            # For opening brackets\n",
    "            else :\n",
    "                stack.append(i)\n",
    "        \n",
    "        return not stack "
   ]
  }
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