From 857ce0f8f5f5d5201c7ec16d74d6f4fa806f30c0 Mon Sep 17 00:00:00 2001
From: tw2665 <55668073+tw2665@users.noreply.github.com>
Date: Thu, 20 May 2021 16:52:58 -0400
Subject: [PATCH] add python solution to 0541.reverseStrII

---
 problems/0541.反转字符串II.md | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/problems/0541.反转字符串II.md b/problems/0541.反转字符串II.md
index 0a92ac8b..75ac39b0 100644
--- a/problems/0541.反转字符串II.md
+++ b/problems/0541.反转字符串II.md
@@ -134,6 +134,36 @@ class Solution {
 ```
 
 Python：
+```python3
+
+class Solution(object):
+    def reverseStr(self, s, k):
+        """
+        :type s: str
+        :type k: int
+        :rtype: str
+        """
+        from functools import reduce
+        # turn s into a list 
+        s = list(s)
+        
+        # another way to simply use a[::-1], but i feel this is easier to understand
+        def reverse(s):
+            left, right = 0, len(s) - 1
+            while left < right:
+                s[left], s[right] = s[right], s[left]
+                left += 1
+                right -= 1
+            return s
+        
+        # make sure we reverse each 2k elements 
+        for i in range(0, len(s), 2*k):
+            s[i:(i+k)] = reverse(s[i:(i+k)])
+        
+        # combine list into str.
+        return reduce(lambda a, b: a+b, s)
+        
+```
 
 
 Go：