Thread: 1st real program in c++

Hi, I am new to c++, and i have been teaching myself from the tutorials listed on this website, and a book that I have. I just finished my first real program whose idea i did not get from a tutorial. It's a program that rolls dice for the boardgame Risk. I know other programs exist for this, i just wanted to try my hand at making my own. What i was wondering was, if anyone wouldnt mind taking a look at the code, or maybe compiling it, and offering some comments, copliments or criticisms. Thanks a lot!

Here is the code.

Code:

/*****************************************************************************
* This program is designed to facilitate the process of rolling dice in the
* boardgame Risk.  The program asks the user how many armies should attack, and
* how many should defend, and how many rounds this should continue for.  There
* is also a simple dice roll function included in the program.  Written by
* Nathan Petts 3.7.06
******************************************************************************/

#include <iostream>
#include <cstdlib>
#include <ctime>
#include <windows.h>

using std::cout;
using std::cin;
using std::endl;



int diceroll (int& dicerollrun); //this function rolls y n-sided die x times

int riskroll (int& riskrun);     //this function exectues the process of 
                                 // determening the winner of an attack in risk

void clrscr (void);              // this windows-specific function clears the
                                 // screen. Written by Sunlight.

int main()
{
    int run = 1; //controlls the loop that keeps the program running
    int input = 0; // menu input
    int dicerollrun; // controlls the loop that keeps the dice roll funct. up
    int riskrun;     // controlls the loop that keeps the riskroll fucnt. up
    
    do {
    cout << "Welcome to RiskCalc. Written by Nathan Petts 3.7.06" << endl;
    cout << "Please make your selection" << endl;
    cout << "1: Risk Calculations" << endl;
    cout << "2: Diceroll" << endl;
    cout << "0: Exit" << endl;
    cin >> input;
    
         switch (input)
         {
           case 1:
                do {
                    riskrun = 1;
                riskroll (riskrun); // calls the riskroll function
                }
                while (riskrun !=0);
               
                break;
           case 2:
                do 
               {
                dicerollrun = 1;
                diceroll (dicerollrun); //calls the diceroll function
                }
                while (dicerollrun !=0);
                break;
           case 0:
                run = 0;
                break;
           default:
                   cout << "invalid input" << endl;
                   run = 0;
                   break;
       
       }   
    }
    while (run != 0);
    
    return 0;
}


int diceroll (int& dicerollrun)
{
     int numdice; //number of dice to roll
     int numsides; // number of sides to each die
     int l;    //loop controll
     srand(time(NULL)); // seed rand w/ time
     cout << "Please enter the number of dice sides. Enter 0 to exit to Main Menu" << endl;
     cin >> numsides;
     cout << "Please enter number of dice." << endl;
     cin >> numdice;
     
     
     if (numsides != 0)
     {                        
       cout << "The dice rolls are:" << endl;
       for (l = 0; l < numdice; l++)
       {
           cout << rand () %numsides + 1 << endl;
           
       }
       system ("pause");
       clrscr();
    }
    else 
    {
        dicerollrun = 0;
        clrscr();
    }
return dicerollrun;
}

int riskroll (int& riskrun)
{
    int numattackers; // the number of attacking armies
    int numdefenders; // the number of defending armies
    int attackingarmieslost = 0; // number of attacking armies lost
    int defendingarmieslost = 0; // number of defending armies lost
    int rounds;             // the number of rounds the dice will be rolled
    int x;            // for-loop control attackarray
    int y;            // for-loop control defendarray
    int z;            // for-loop control compairing the arrays
    int n;            // for-loop controll for number of rounds
    srand(time(NULL)); // seeding random
    int temp;          //temp int for sorting
    
    cout << "enter number of rounds to attack. enter 0 to exit" << endl; 
    cin >> rounds;
    cout << "enter number of attacking armies. enter 0 to exit" << endl;
    cin >> numattackers;
    cout << "enter number of defending armies. enter 0 to exit" << endl;
    cin >> numdefenders;
    
    int attackarray [numattackers];    // the dice rolls of the attackers
    int defendarray [numdefenders];    // the dice rolls of the defenders
    
    if (numattackers != 0 && numdefenders != 0 && rounds != 0)
    {
    for (n = 0; n < rounds; n++)
    {
       for (x = 0; x < numattackers; x++)
        {
        attackarray [x] = rand () %6 + 1;
        }
    
    
       // sorts attackarray
       for(int x=0; x< numattackers; x++)
	   {
		for(int y=0; y<numattackers-1; y++)
		{
			if(attackarray[y]<attackarray[y+1])
			{
				int temp = attackarray[y+1];
				attackarray[y+1] = attackarray[y];
				attackarray[y] = temp;
			}
	     }
	    }
        /*
        cout << "these are the attackers rolls" << endl;
    
        for (x = 0; x < numattackers; x++)
        {
        cout << attackarray [x] << endl;
        }*/
    
        for (y = 0; y < numdefenders; y++)
        {
            defendarray [y] = rand () %6 + 1;
        }
   
        // sorts the defendarray
         for(int x = 0; x < numdefenders; x++)
	     {
		        for(int y=0; y<numdefenders-1; y++)
		        {
                        if(defendarray[y]<defendarray[y+1])
			            {
                        int temp = defendarray[y+1];
				        defendarray[y+1] = defendarray[y];
				        defendarray[y] = temp;
                        }
                }
	     }
         /*cout << "these are the defender rolls" << endl;
    
         for (y = 0; y < numdefenders; y++)
         {
                cout << defendarray [y] << endl;
         }*/

         for (z = 0; z < numdefenders; z++)
             {
             if (defendarray [z] >= attackarray [z])
             {
                       attackingarmieslost++;
             }
             else 
             {
                  defendingarmieslost++;
             }
             } 
             
             
         }      
   cout << "the attackers lost " << attackingarmieslost << " armies." << endl;
   cout << "the defenders lost " << defendingarmieslost << " armies." << endl;
   system ("pause");
   clrscr();
   riskrun = 1;
   }
   else 
   {
     riskrun = 0;
     clrscr();
   }   

    return riskrun;
}

void clrscr(void)
{
    COORD                       coordScreen = { 0, 0 };
    DWORD                       cCharsWritten;
    CONSOLE_SCREEN_BUFFER_INFO  csbi;
    DWORD                       dwConSize;
    HANDLE                      hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
    GetConsoleScreenBufferInfo(hConsole, &csbi);
    dwConSize = csbi.dwSize.X * csbi.dwSize.Y;
    FillConsoleOutputCharacter(hConsole, TEXT(' '), 
                               dwConSize, coordScreen, &cCharsWritten);
    GetConsoleScreenBufferInfo(hConsole, &csbi);
    FillConsoleOutputAttribute(hConsole, csbi.wAttributes, 
                               dwConSize, coordScreen, &cCharsWritten);
    SetConsoleCursorPosition(hConsole, coordScreen);
}

Mabe work on naming conventions for your variables

The program looks good. One question is why are you returning a value when it is not being used. Also, in C++ you generally want to declare the variables only when you are ready to initialize and use them. So while it will work either way, the variable declarations should probably be moved to where they are first needed.

the functions that return values are returning them so that the functions will continue to repeat untill terminated by the user. I dont think that this is a very elegant solution to that problem, however, so if there is another way, by all means, inform me.

thanks for the note about variable declarations, i will modify the code accordingly.

thanks for the comments.

From what I can tell, you aren't using the return values. For example, you have this code:

Code:

diceroll (dicerollrun);

It ignores the return value. It works because you pass the argument by reference and so dicerollrun is updated. You might as well have the functions return void instead of int because there is no need for a return value, the reference parameter handles the function output.

heard and understood.

>> since the original int& dicerollrun is used purely as a return type, that's what it should be.

I didn't read it closely enough to see that. I agree.