newbie: find largest number

[KhuntienNang]

Hello, im new in c++. im learning by myself online and from a textbook, using dev-c++ as my compiler.

right now im trying to do exercises from a textbook (C++ how to program, deitel), and currently im stuck on 2 questions.

first one, is about finding the two largest numbers out of 10 integers entered by user. here is what i got, but i think my second largest number is still wrong, and for some reason my last two couts dont print. any suggestion?

// Ex. 4.19 //

#include <iostream>
using namespace std;

int main (){
    
    int counter=0, num, large1=0, large2=0;
    
    cout << "Enter an integer: ";
    
    while (counter<10){
          cin >> num;
          if (large1 < num)
             large1 = num;
          if (large2 < num && large2 < large1)
             large2 = num;
          ++counter;
    
          }
    cout << "Largest number: " << large1;
    cout << "\nsecond largest: " << large2;  
    cin.get();
}                                     
    

the second problem:
im trying to print a diamond by "*" and " "(space) using for statement. but i can't figure out the logic for it. i could print a triangle by nested for, but can't do the diamond, any clue?

Thanks!

[z05DSL3A]

#include <iostream>
using namespace std;


int main ()
{
    int counter = 0; 
    int num = 0;
    int large1 = 0; 
    int large2 = 0;
    
    while (counter < 10)
    {
        cout << "[" << counter << "] Enter an integer: ";  
        cin >> num;
        cin.get();  // This just clears the new line from the stream
                    // don't worry about it too much at the moment.

        if (large1 < num)
        {
            large2 = large1;
            large1 = num;
        }
        else if (large2 < num )
        {
            large2 = num;
        }
        ++counter;
    }
    cout << "Largest number: " << large1 << endl;
    cout << "Second largest: " << large2 << endl;  
    
    system("pause");
} 

[KhuntienNang]

what exactly is the difference between cin.get() and system("pause")? i read somewhere that cin.get() supposed to get the effect of system("pause"), that's why i have always include that line in every script i wrote, though sometimes it doesnt pause.

now i know system("pause") will do the trick, i will keep using that from now on :p

now what confuses me is, why sometimes the window will disappear after it runs, sometimes doesnt?

[z05DSL3A]

Okay, system() basically asks the operating system to run a program, so system("pause") asks the OS to run pause.exe. pause.exe displays ‘press any key to continue’ and then waits for a key to be pressed. Control is then passed back to your program.

Onto cin.get(), gets a character from the stream (cin) and returns its value (casted to an integer). If there is ‘junk’ in the stream a call to get will return and your program will carry on.

Does that help?

[KhuntienNang]

thanks greywolf! :D

i have another question, where I have to find the product of odd integers from 1 to 15. im trying to do it with 2 approaches: one using for loop with increment of 2 (which i got it to work with correct answer), and another approach i tried doing is by using modulus, but somehow i got wrong answer.

could someone check what's wrong with my code?

#include <iostream>
using namespace std;

int main(){
    int odd=1, test;
    for (int x=1; x<16; x++){
        test = x%2;
        if (test=1){
           odd = odd*x;
        }
        else {
             break;
        }
    }
    cout << "Product of odd integers from 1 to 15: "<<odd<<endl;
    system("pause");
}

[z05DSL3A]

This is just a bit of advice for posting.
If you have a new question (not related to the original question), it is better to start a new thread, because you may restrict your 'viewing' audience to only the people currently taking part in the current thread if you don't.

[rpgfan3233]

Your problem is the "if (test=1){" part, I think. It should be "if (test==1){" because = is for assigning one value to another and == is for comparing two values.

As Grey Wolf mentioned, if you have a completely new question, please start a new thread. It helps with organization (less scrolling), and it helps future programmers with the same problem because they can search.

I hope this helps! ^_^

rpgfan

[nnzzyy]

I think you should use "continue" instead of "break" in your program. Otherwise, it will break when x=2.

[rpgfan3233]

nnzzyy wrote:
> I think you should use "continue" instead of "break" in your program.
> Otherwise, it will break when x=2.

True, though technically, that means the else statement is unnecessary since it will automatically continue. ^_^

[z05DSL3A]

...
    for (int x = 1; x < 16; x++)
    {
        if ( (x % 2) != 0)
        {
           odd *= x;
        }
    }
...

[KhuntienNang]

thanks a lot! :D you all are right, i tried your advices, they all solve the problem :D thanks

i will create new topic if there is more new question.