请编写一个C函数,该函数将一个字符串逆序

#include <stdio.h>

int mystrlen(const char *str)  //计算字符串的长度

{
int length = 0;

if (str == NULL)
{
return -1;
}

while (*str++)
{
length++;
}
return length;

}

void RevStr(char *str)

{
int i = 0;
char temp = 0;
int len = mystrlen(str);

for (i = 0; i < len / 2; i++) //字符串倒置
{
temp = str[i];
str[i] = str[len - i - 1];
str[len - i - 1] = temp;
}

}

int main()

{
char str[10] = "hello"; //定义字符串

printf ("The original string is : ");
printf ("%s\n", str);

RevStr(str);
printf ("The result is : \n");
printf ("%s\n", str);

return 0;

}