#include <stdio.h>

char toupper(char ch) { 
     return (  ((ch >= 'a') && (ch <= 'z')) ? (ch-32): ch ); 
}

int main()
{
    printf("Introduza um caracter:\n");
    char c = getchar();
    
    printf("Respectivo caracter maiusculo: %c", toupper(c));
    
    return 0;
}