LintCode——旋转字符串

描述：给定一个字符串和一个偏移量，根据偏移量旋转字符串(从左向右旋转)

样例：对于字符串 "abcdefg" 

　　   offset=0 => "abcdefg"

　　   offset=1 => "gabcdef"

　　   offset=2 => "fgabcde"

　　   offset=3 => "efgabcd"

1、Python

 class Solution:
     """
     @param str: An array of char
     @param offset: An integer
     @return: nothing
     """
     def rotateString(self, str, offset):
         # write your code here
         if not offset: return   #无偏移量
         if not str: return      #字符串是空串

         offset = offset % len(str)
         for i in range(offset): #字符串旋转
             c = str.pop()
             str.insert(0,c)
         return str

2、Java

 public class Solution {
     /**
      * @param str: An array of char
      * @param offset: An integer
      * @return: nothing
      */
     public void rotateString(char[] str, int offset) {
         // write your code here
         char temp;
         if(offset == 0) return;     //偏移量为0
         if(str.length == 0) return; //字符串为空串

         int len=str.length;
         for(int i = 1;i <= offset % len;i++){
             temp = str[len - 1];
             int j = len - 2;
             while(j >= 0){
                 str[j + 1] = str[j];
                 j--;
             }
             str[0]=temp;
         }
     }
 }