c语言reverse在线卑微求解

#include <stdio.h>
#include <string.h>
#include <malloc.h>

void fun_reverse(const char* str, char* desc) {
    int len = strlen(str);
    str = str + len - 1;
    while (*str != '\0') {
        *desc++ = *str--;
    }
    *desc = '\0';
    desc = desc - len;
}

int main()
{
    const char* src = "I am a student.";
    char* des = (char*)malloc(100 * sizeof(char));
    fun_reverse(src, des);
    printf("%s \n", des);
    return 0;
}