关于#c++#的问题：将字符串循环右移n个字符，例如abcde循环右移两位

Question

定义函数，将字符串循环右移n个字符，例如abcde循环右移两位:deabc
函数接口定义：
void fun(char ＊str,int n)

Answer 1

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
void fun(char ＊str,int n);
 
int main()
{
    char s[20];
    int n;
    scanf("%s%d",s,&n);
    fun(s, n);
    printf("%s", s);
    return 0;
}


void fun(char *str,int n)
{
    if ((str == NULL) || (n <= 0)) {
        return;
    } 
 
    int nLen = strlen(str);
    if (n >= nLen) {
        n = n % nLen;
    }
    
    char* pHead = (char*)malloc(n * sizeof(char));
    char* pTail = (char*)malloc((nLen - n) * sizeof(char));
    memset(pHead, 0 ,sizeof(pHead));
    memset(pTail, 0, sizeof(pTail));
    memcpy(pHead, str + nLen - n, n);
    memcpy(pTail, str, nLen - n);
 
    memcpy(str, pHead, n);
    memcpy(str + n , pTail, nLen - n);
    return;
}