WTF #2

This must be work of some dark evil mastermind.

void  DECIMAL_TO_HEXA( int num, char *hex )
{
     int aux_hex[32],i=0;
     char hexa[32], resu[32];
 
     while(num>0) {
         aux_hex[i]=num%16;
         num/=16;
         i++;
     }
 
     resu[0]='\0';
     i--;
     for(i;i>=0;i--) {
         if (aux_hex[i]<10) { 
                 sprintf(hexa, "%d", aux_hex[i]); 
                 strcat(resu, hexa); 
         }
         else if (aux_hex[i]==10) strcat(resu, "A"); 
         else if (aux_hex[i]==11) strcat(resu, "B"); 
         else if (aux_hex[i]==12) strcat(resu, "C"); 
         else if (aux_hex[i]==13) strcat(resu, "D"); 
         else if (aux_hex[i]==14) strcat(resu, "E"); 
         else if (aux_hex[i]==15) strcat(resu, "F"); 
     } 
     strcpy(hex, resu);
}