EDIT: I've fixed it, thanks for the help guys! :D On C++. Yeah.. our teacher basically just gives us homework and tells us to read the book. I've read the book we're supposed to read and it doesn't tell me anything about how to do this, so I've come to you guys for help. Here are the instructions: 1. Prompts the user to input 2 numbers - firstNum and secondNum. Make sure that firstNum is less than secondNum. If it is not, the user should get an error message and be prompted again to enter the values. ... uses while loops to perform the following steps: 2. Output all odd numbers between firstNum and secondNum. 3. Output the sum of all even numbers between firstNum and secondNum. 4. Outputs the numbers and their squares of all numbers between firstNum and secondNum. 5. Outputs the numbers from secondNum to firstNum as a countdown sequence Here is the code I have so far, I'm not sure if it's correct or not:

#include <iostream>
#include <iomanip>
using namespace std;

int main()
{
    int firstNum, secondNum, squareNum, counter, counterT, counterR, counterU;
    int sum = 0;
    
    cout << "The first number must be less than the second number.\n\n";
    cout << "Enter 1st number: ";
    cin >> firstNum;
    cout << "Enter 2nd number: ";
    cin >> secondNum;
    
    counterT = secondNum;
    counterU = secondNum;
    if (secondNum % 2 == 1)
    {
       counter = secondNum - 2;
       counterR = secondNum - 1;
    }
    else
    {
       counter = secondNum - 1;
       counterR = secondNum - 2;
    }
        
    if (firstNum < secondNum)
    {
                 cout << "Odd numbers: ";
                 do
                 {
                               cout << counter << " ";
                               counter -= 2;
                 } while(counter >= firstNum);
                 cout << "\n";
                 cout << "Sum of even numbers: ";
                 do
                 {
                               sum+=counterR;
                               counterR -= 2;
                 } while (counterR >= firstNum);
                 cout << sum;
                 cout << "\n";
                 cout << "Squares of numbers: ";
                 do
                 {
                               cout << (counterU * counterU) << " ";
                               counterU--;
                 } while(counterU >= firstNum);
                 cout << "\n";
                 cout << "Countdown: ";
                 do
                 {
                               cout << counterT << " ";
                               counterT--;
                 } while(counterT >= firstNum);
                 cout << "\n";
    }
    else
    cout << "Your first number is not less than your second number.\n";  
    
    
    system("pause");
    return 0;
}

[Edited by - Ultimatepuff on July 21, 2009 4:05:44 PM]

Quote:Original post by Haptic
What specifically are you having trouble with?

I don't know how to do parts 2-4, and I'm not sure if I did part 5 right either.

Quote:Original post by dmatter
That isn't a complete program, I think you've only pasted as fragment of what you really have, if it's much longer than that though then I recommend you use source tags intead.

Well a fragment is actually all I have, I don't know where to start on the rest because I'm new/suck at programming like that.

Quote:Original post by tnutty
"int firstNum, secondNum, oddNum, sum, evenNum, betweenNum, squareNum, counter;
counter = secondNum;"

counter = secondNum is a bug because secondNum is initialized. This would cause
the program to crash

it wouldn't cause a crash, it would just set counter to an uninitialized value (secoondNum could be any number), but it won't crash.

Exactly. Your code will not work because counter will not be equal to secondNum because the assignment is done before secondNum itself has a value!



If you look at the code, you will see that you have declared all of those variables, however the user hasn't entered the two numbers yet, so counter will not be equal to the value of secondNum later on.

Just think about where you should move the assignment so that counter has the proper value of secondNum after the user has entered it.

For #2, you can see whether or not a number is odd by using the % operator, which returns the remainder between two numbers. Knowing that any even number divided by 2 has a remainder of zero, it is a simple task to see whether or not a number is odd or not.

All in the same loop, you can output all of the odd numbers by seeing if the remainer between the number and 2 is not 0, and if it is zero, then it is an even number, and for problem #3, you can add it to the sum variable (remember to initialize that variable at 0!).

Knowing that, I am sure you can figure out problem #4. You can either implement your own function for squaring numbers (as there is no operator for squaring a number in C++) or you can use the function in the math library.