C

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>





#define ENDSEQ -1
#define PROMO_NONE 'N'
#define PROMO_3x2  'T'
#define PROMO_2x1  'D'
#define PROMO_HALF 'M'
#define PROMO_LOYALTY 0.95




float computeNoPromoPrice (float price, int qtt, float VAT)
{
    return price * (float) qtt * VAT;
}

float computeNxMPromoPrice (int N, int M, float price, int qtt, float VAT){


    float promo, noPromo;

    promo = (float) qtt / N * (float) M * price * VAT;
    noPromo = (float)(qtt % N) * price * VAT;

    return promo + noPromo;
}

float computeHalfPromoPrice (float price, int qtt, float VAT){

    float promo, noPromo;

    noPromo = (float) qtt / 2 + (float) (qtt % 2) * price * VAT;
    promo = (float) qtt / 2 * price * 0.5 * VAT;

    return promo + noPromo;
}

/*Declaracio de accions*/

void addToAmount (float *amount, float price, int qtt, char promo, float VAT){

    float productPrice;

    productPrice = 0.0;

    if (promo == PROMO_NONE){
        productPrice = computeNoPromoPrice(price, qtt, VAT);
    }else{
        if(promo == PROMO_3x2){
            productPrice = computeNxMPromoPrice(3, 2, price, qtt, VAT);
        }else{
            if(promo == PROMO_2x1){
                productPrice = computeNxMPromoPrice(2, 1, price, qtt, VAT);
            }else{
                productPrice = computeHalfPromoPrice (price, qtt, VAT);
            }
        }
    }

    *amount = &amount + productPrice;
}


int main()
{

    bool loyaltyCard;
    int code, qtt, percent;
    char promo, card, blank;
    float price, VAT, amount;

    amount = 0.0;
    scanf("%c", &card);
    loyaltyCard = card = 'S';
    scanf("%c", &blank);
    scanf("%d", &code);

    while( code != ENDSEQ ){
        scanf("%f", &price);
        scanf("%d", &qtt);
        scanf("%c", &blank);
        scanf("%c", &promo);
        scanf("%c", &blank);
        scanf("%d", &percent);

        VAT = 1.0 + (float) percent / 100.0;
        addToAmount (&amount,price,qtt,promo,VAT);
        scanf("%d", &code);
    }

    if (loyaltyCard) {
        amount = amount * PROMO_LOYALTY;
    }

    printf("%.2f", amount);

    return 0;
    system ("PAUSE");
}