Untitled

#include <stdio.h>
char *ft_strupcase(char *str)
{
    while ( *str != 0)
    {
        if (*str >= 'A' && *str <= 'Z')
        {
            *str = *str-('A'-'a');
        }
        str++;
    }
    return str;
}
int main() 
{
    char i[] = "fSuHGUIUigGS";
    ft_strupcase(i);
    printf("%s", i);
    return 0;
}