【C语言】字符串右循环移位

比如：“abcdefghi”循环右移2位就是：“hiabcdefg”

给定函数原型：void RightLoopMove(char *pStr,unsigned short steps)

方法一：首先将最后面一个字符赋给临时变量，再将前面字符依次往后挪动一个位置，最后把临时变量赋给第一个字符。

#include <stdio.h>
#include <string.h>
void RightLoopMove(char *pStr, unsigned short steps)
{
    char *l = pStr;
    char *r = pStr + strlen(pStr) - 1;
    while (steps)
    {
        char tmp = *r;
        char *p = r;
        while (p > l)
        {
            *p = *(p - 1);
            p--;
        }
        *l = tmp;
        steps--;
    }
}
int main()
{
    char a[] = "abcdefghi";
    RightLoopMove(a,2);
    printf("%s\n", a);
    return 0;
}

方法二：三次翻转字符串

#include <stdio.h>
#include <string.h>
void reverse(char *l, char *r)
{
    while (l < r)
    {
        char tmp = *l;
        *l = *r;
        *r = tmp;
        l++;
        r--;
    }
}
void RightLoopMove(char *pStr, unsigned short steps)
{
    int n = strlen(pStr);
    reverse(pStr, pStr+n-steps-1);
    reverse(pStr + n - steps,pStr+n-1);
    reverse(pStr,pStr+n-1);
}
int main()
{
    char a[] = "abcdefghi";
    RightLoopMove(a,2);
    printf("%s\n", a);
    return 0;
}