leetcode mmistakes#20

_posts/algorithm/string/2022-05-04-20-Valid Parenthese.md

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+---
+layout: single
+title: "[string] Leetcode #20 valid parenthese"
+categories: ["string"]
+tag: [algorithm, string, leetcode]
+toc: true
+toc_label: "Table of Contents"
+toc_icon: "align-justify" # corresponding Font Awesome icon name (without fa prefix)
+toc_sticky: true
+---
+
+># description of the problem
+
+finding right mate of parenthese
+
+># logic 
+
+using the stack method which means `Last in, first out`.
+
+```Python
+class Solution:
+    def isValid(self, s: str) -> bool:
+        cha ={"(":")","[":"]","{":"}"}
+        stack = []
+        for i in range(len(s)):
+            parenthese = s[i]
+            if parenthese in cha.keys():
+                stack.append(parenthese)
+            else :
+                if stack == []:
+                    return False
+                else:
+                    pop = stack.pop()
+                    if parenthese != cha[pop]:
+                        return False
+        if stack == []:
+            return True
+
+
+
+```