#include "libft.h"
/*
* ft_toupper() function that converts a lowercase letter to uppercase.
* Returns the uppercase equivalent of the input character 'c',
* or the character itself if 'c' is not a lowercase letter.
*/
int ft_toupper(int c)
{
if (c >= 'a' && c <= 'z')
c -= 'a' - 'A';
return (c);
}