对于循环灾难，它会进行更多的迭代

Question

Can someone help me find out what this would iterate 3 times when i tell it to only do one time int the forloop? I choose my mtype 1 and when i go to display that information(which this function is designed to do) it loops the 3 times instead of one.

EDIT: the reason i know its iterating more than it should is because the cout statement at the bottom of each if statement doesnt actually go there, im just using it to find where the problem is.

for (int itemno = 0; itemno < numItems; itemno++)
{

    if (mtype == *(type + itemno) || mtype == -1)
    {
        if (mtype == 2)
        {

            *(price + itemno) = calculatePrice(*(cost + itemno), *(hours + itemno));

            totalCost = totalCost + *(cost + itemno);
            totalHour = totalHour + *(hours + itemno);
            totalPrice = totalPrice + *(price + itemno);
            cout << setw(13) << left << canType << setw(13) << right << *(cost + itemno) << setw(16) << setprecision(2) << fixed << hours[itemno] << setw(16) << price[itemno] << endl << endl;
        }
    }
    else if (mtype == *(type + itemno) || mtype == -1)
    {
        if (mtype == 3)
        {

            *(price + itemno) = calculatePrice(*(cost + itemno), *(hours + itemno));

            totalCost = totalCost + *(cost + itemno);
            totalHour = totalHour + *(hours + itemno);
            totalPrice = totalPrice + *(price + itemno);
            cout << setw(13) << right << *(cost + itemno) << setw(16) << setprecision(2) << fixed << hours[itemno] << setw(16) << price[itemno] << endl << endl;

        }
    }
    else if (mtype == *(type + itemno) || mtype == -1)
    {
        if (mtype == 4)
        {

            *(price + itemno) = calculatePrice(*(cost + itemno), *(hours + itemno));

            totalCost = totalCost + *(cost + itemno);
            totalHour = totalHour + *(hours + itemno);
            totalPrice = totalPrice + *(price + itemno);
            cout << setw(13) << right << *(cost + itemno) << setw(16) << setprecision(2) << fixed << hours[itemno] << setw(16) << price[itemno] << endl << endl;
        }
    }
    else if (mtype == *(type + itemno) || mtype == -1)
    {
        if (mtype == 5)
        {
            *(price + itemno) = calculatePrice(*(cost + itemno), *(hours + itemno));

            totalCost = totalCost + *(cost + itemno);
            totalHour = totalHour + *(hours + itemno);
            totalPrice = totalPrice + *(price + itemno);
            cout << setw(13) << right << *(cost + itemno) << setw(16) << setprecision(2) << fixed << hours[itemno] << setw(16) << price[itemno] << endl << endl;
        }
    }   
    cout << setw(13) << right << *(cost + itemno) << setw(16) << setprecision(2) << fixed << hours[itemno] << setw(16) << price[itemno] << endl << endl;
}


cout << endl << setw(9) << left << "TOTALS: " << setw(5) << right << "$" << setw(12) << totalCost<< setw(17) << totalHour << setw(17) << "$" << setw(5) << totalPrice << endl;
cout << endl << horizontalLine << endl << endl;

}

Answer 1

Look at all that repetition. Try this:

if (mtype >= 2 && mtype <= 5) {
    for (int itemno = 0; itemno < numItems; itemno++) {
        if (mtype == type[itemno]) {
            price[itemno] = calculatePrice(cost[itemno], hours[itemno]);
            totalCost += cost[itemno];
            totalHour += hours[itemno];
            totalPrice += price[itemno];

            if (mtype == 2) cout << setw(13) << left << canType;
            cout << setw(13) << right << cost[itemno]
                 << setw(16) << setprecision(2) << fixed << hours[itemno]
                 << setw(16) << price[itemno] << "\n\n";
        }
    }
}
cout << "\n" << setw(9) << left << "TOTALS: "
             << setw(5) << right << "$" << setw(12) << totalCost
             << setw(17) << totalHour
             << setw(17) << "$" << setw(5) << totalPrice << "\n\n";
cout << horizontalLine << "\n\n";
cout << flush;