请编写一个C函数，将一个字符串逆序

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

char* str_reverse(char* str)
{
    int n = strlen(str) / 2;
    int i = 0;
    char tmp = 0;
    
    for(i = 0; i < n; i++)
    {
        tmp  = str[i];
        str[i] = str[strlen(str)-i-1];
        str[strlen(str)-i-1] = tmp;
    }

    return str;
}

int main()
{
    char s[] = "hello world!";

    printf("str_reverse(s) = %s\n", str_reverse(s));

    return 0;
}