字符串：左旋和右旋

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/*左旋*/
char move_steps(char *msg, int steps) {
       int i = 0;
       int len = strlen(msg);
       steps = steps % len;  //保證移動的位數在字符串長度範圍內   
       while (steps) {
              char tmp = msg[0];
              for (i = 0; i < len - 1; i++) {
                     msg[i] = msg[i + 1];
              }
              msg[i] = tmp;
              steps--;
       }
       return msg;
}
/*右旋*/
char RightLoopMove(char *pStr, unsigned short steps)
{
       int len = strlen(pStr);
       steps = steps % len;
       int i = 0;
       while (steps) {
              char tmp = *(pStr + len - 1);
              for (i = len - 1; i > 0; i--) {//注意不要越界
                     *(pStr + i) = *(pStr + i - 1);
              }
              pStr[i] = tmp;
              steps--;
       }
       return pStr;
}
int main()
{
       char p[] = "abcdef";
       //move_steps(p, 2);
       RightLoopMove(p, 2);
       printf("%s\n",p);
       system("pause");
       return 0;
}