a20

README.md

@@ -22,6 +22,8 @@ leetcode 题解
 
 [19. Remove Nth Node From End of List](Solution/1-50/19.md)
 
+[20. Valid Parentheses](Solution/1-50/20.md)
+
 [21. Merge Two Sorted Lists](Solution/1-50/21.md)
 
 [29. Divide Two Integers](Solution/1-50/29.md)

Solution/1-50/20.md

@@ -0,0 +1,23 @@
+# 20. Valid Parentheses
+[题目链接](https://leetcode.com/problems/valid-parentheses/#/description)
+
+```python
+class Solution(object):
+    def isValid(self, s):
+        """
+        :type s: str
+        :rtype: bool
+        """
+        kv_dict = {'{': '}', '(': ')', '[': ']'}
+        data_list = []
+        for i in range(len(s)):
+            c = s[i]
+            if c in kv_dict.keys():
+                data_list.append(c)
+            elif c in kv_dict.values():
+                if len(data_list) == 0 or c != kv_dict[data_list.pop()]:
+                    return False
+        if(len(data_list) > 0):
+            return False
+        return True
+```