如果语句为真，我如何只显示printf语句？

Question

我正在制作一个运输计算器，如果包装重量超过50磅，则无法运送包裹。我只想在包装重量超过50磅的情况下发表声明，但无论如何都会出现。

我尝试将其作为else语句，if语句和if else语句。

main(){
    double distance, weight, weightCharges, shippingCharge, distanceCharge, unableToShip;
    printf ("Enter the weight of the package:\n");
    scanf ("%lf", &weight);
    printf ("Enter the distance your package needs to go: \n");
    scanf ("%lf", &distance);

    if (weight <= 10)
        weightCharges = weight * 3.00;
        else
            if (weight <= 50)
                weightCharges = weight * 5.00;
            else (weight > 50);
        weightCharges= 0;
    if (distance > 1000)
        distanceCharge = weightCharges + 10;
    shippingCharge = weightCharges + distanceCharge;
    unableToShip = weight > 50;

    printf ("Your total cost is: %.2lf \n", shippingCharge);
    printf ("We're unable to ship your package \n", unableToShip);

}

我希望第二个printf仅在我们无法发送包装时出现，但无论如何都会出现。