43.左旋转字符串(python)

1 class Solution:
2     def LeftRotateString(self, s, n):
3         # write code here
4         return s[n:]+s[:n]

 1 class Solution:
 2     def LeftRotateString(self, s, n):
 3         # write code here
 4         if s == "":
 5             return ""
 6         s=list(s)
 7         self.reverse(s,0,n-1)
 8         self.reverse(s,n,len(s)-1)
 9         self.reverse(s,0,len(s)-1)
10         return ‘‘.join(s)
11     def reverse(self,s,low,high):
12         while low < high:
13             s[low],s[high]=s[high],s[low]
14             low+=1
15             high-=1