Thread: Random Problem?

Okay i have this problem with the output, it displays all off the random numbers in their array except for the last array. The last array is filled with pretty much nonsense. I have tried a few things but cannot get it to work. Another problem is the random numbers are the exact same every time i run the program, such as array 1 will be 22 and array 2 will be 56 every single time i run the program.

PHP Code:

/****************************************************
          Random Lists - awlists.cpp
-----------------------------------------------------
Using 1D arrays and looping structures, display the
contents of an array filled with random numbers.
-----------------------------------------------------
              Coded by: Andrew Weir
               November 20th,2002
****************************************************/

#include<iostream.h>
#include<iomanip.h>
#include<conio.h>
#include<string.h>
#include<math.h>
#include<time.h>
#include<stdlib.h>

struct info
{
        char userResponse;
        //used to repeat the program
        int iCounter, rowCounter, arrayNumber, arrayActual[30], arrayCounter, randomNumber;
        //iCounter used for the loop in the outputForm function
        //rowCounter used to make sure it prints 5 items per row
        //arrayNumber used for the user input for amount of arrays
        //arrayActual is the actual array holding the random numbers
        //arrayCounter is used in the rndmProcedure function in the for loop
        //randomNumber is used to generate the random numbers
        string firstName, lastName, fullName;
};

info vars;

void fowlerStatement()
{
        gotoxy(25,2);
        cout<<"Random Lists";
        gotoxy(25,3);
        cout<<"~~~~~~~~~~~~";
        gotoxy(5,5);
        cout<<"This program will ask the user to input a number";
        gotoxy(5,6);
        cout<<"of arrays while the computer randomly fills each";
        gotoxy(5,7);
        cout<<"          array with a random number.";
        //gotoxy(5,8);
        //cout<<"         The number is between 1-10.";
        gotoxy(5,10);
        cout<<"This program was written in C++ by: Andrew Weir";
        getch();
}

void inputForm(info& vars)
{
        clrscr();
        gotoxy(25,2);
        cout<<"Random Lists";
        gotoxy(25,3);
        cout<<"~~~~~~~~~~~~";
        gotoxy(5,5);
        cout<<"Please enter your first name: ";
        cin>>vars.firstName;
        gotoxy(5,7);
        cout<<"Please enter your last name: ";
        cin>>vars.lastName;
        vars.fullName = vars.lastName+", "+vars.firstName;
        gotoxy(5,9);
        cout<<"Please enter the amount of numbers to be generated: ";
        cin>>vars.arrayNumber;
        if(vars.arrayNumber>30)
        {
                do
                {       gotoxy(42,10);
                        cout<<"             ";
                        gotoxy(5,10);
                        cout<<"Please enter a number lower than 30: ";
                        cin>>vars.arrayNumber;
                }
                while(vars.arrayNumber>30);
        }
}

void rndmProcedure(info& vars)
{
        randomize;
        for(vars.arrayCounter = 0; vars.arrayCounter != vars.arrayNumber; vars.arrayCounter++)
        {
                vars.randomNumber = random(99)+1;
                vars.arrayActual[vars.arrayCounter] = vars.randomNumber;
        }
}

void outputForm(info& vars)
{
        clrscr();

        /*gotoxy(1,1);
        time_t t = time(NULL);
        cout<<ctime(&t);
        gotoxy(25,3);
        cout<<"Random Lists";
        gotoxy(25,4);
        cout<<"~~~~~~~~~~~~";
        gotoxy(5,6);
        cout<<"Name of client: ";
        cout<<vars.fullName;
        gotoxy(40,6);
        cout<<"Array # Limit: ";
        cout<<vars.arrayNumber;*/
        vars.rowCounter=0;
        vars.iCounter=0;

        do
        {
                vars.iCounter++;
                vars.rowCounter++;
                cout<<setiosflags(ios::right);
                //if(vars.iCounter!=vars.arrayNumber)
                //{
                        cout<<vars.arrayActual[vars.iCounter]<<" ";
                //}
                if(vars.rowCounter>=6)
                {
                        cout<<endl;
                        vars.rowCounter=0;
                }
        }
        while(vars.iCounter!=vars.arrayCounter);
        getch();
        //gotoxy(15,12);
        //cout<<"-Thank You for using Random Lists-";
}

main()
{
        info vars;
        fowlerStatement();
        do
        {
                inputForm(vars);
                rndmProcedure(vars);
                outputForm(vars);
                gotoxy(15,14);
                cout<<"Would you like to try agin (y/n): ";
                cin>>vars.userResponse;
        }
        while(vars.userResponse=='y' || vars.userResponse=='Y');
} 


Any help is greatly appreciated.

Looks to me like you've got your do-while loop backwards. You have:

Code:

do {
    vars.iCounter++;
    vars.rowCounter++;
    cout<<setiosflags(ios::right);
    cout<<vars.arrayActual[vars.iCounter]<<" ";
    if(vars.rowCounter>=6) {
        cout<<endl;
        vars.rowCounter=0;
    }
} while(vars.iCounter!=vars.arrayCounter);

which means that you are calling for array elements 1 to n for an n-sized array. The problem with that is that a n-sized array has indices from 0 to n-1, so you are skipping the first and overrunning the last element. When you call for array[n] you are retrieving whatever happens to be living in that memory slot, which is probably garbage. You should write the loop like this:

Code:

while (vars.iCounter != vars.arrayCounter) {
    cout<<setiosflags(ios::right);
    cout<<vars.arrayActual[vars.iCounter++]<<" ";
    if(vars.rowCounter++ >= 6) {
        cout<<endl;
        vars.rowCounter=0;
    }
}

(note that I have moved some of the increments to inside some other expressions). Try this and see if it works.

awesome
thanx a lot that helped!

got it!
srand(time(NULL));

thanx for all the help guys!