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Stopping same number from appearing twice?

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Join Date: Apr 2008

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Black Magic Black Magic is offline

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Stopping same number from appearing twice?

Jun 21st, 2008

Hey, my dad was checking the "lotto" results so that inspired me to make a little program of my own, i accomplished that just got a problem..

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <iostream>
 
using namespace std;
 
int main()
{
    srand(time(NULL));
 
    unsigned int lotteryBall;
 
    for(int i = 0; i <=7; ++i)
    {
            lotteryBall = rand() % 48 + 1;
 
            cout << lotteryBall << " ";
 
            if(i == 7)
                 cout << "*" << lotteryBall << "*";
    }
 
    cin.get();
 
    return 0;
}
#include <iostream>

using namespace std;

int main()
{
    srand(time(NULL));
    
    unsigned int lotteryBall;
    
    for(int i = 0; i <=7; ++i)
    {
            lotteryBall = rand() % 48 + 1;
            
            cout << lotteryBall << " ";
            
            if(i == 7)
                 cout << "*" << lotteryBall << "*";
    }
    
    cin.get();
    
    return 0;
}

I compiled and ran the code and got : 13 19 20 9 31 12 37 46 *46*

But obviously you can't have 46 twice, so I'm not sure how I could change it.

And before you say "the numbers need to go in order from smallest to largest" I will add bubble sort after I have got the main problem solved.

Many thanks.

Last edited by Black Magic; Jun 21st, 2008 at 6:10 am.

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Re: Stopping same number from appearing twice?

Jun 21st, 2008

The reason you got 46 twice there isn't because the random number happends to be the same, its because you are printing the same variable twice without modifying it. If you want to make it so each number can only come up once, you have to make an array for the numbers to go into it and then check it to see if it has already been added.

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Tigran

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Re: Stopping same number from appearing twice?

Jun 21st, 2008

I've modified the script a bit

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <iostream>
 
using namespace std; 
 
int main()
{
    srand(time(NULL));
 
    unsigned int lotteryBall;
 
    for(int i = 0; i <=7; ++i)
    {
            lotteryBall = rand() % 48 + 1;
 
            cout << lotteryBall << " ";
 
            if(i == 7)
                 lotteryBall = rand() % 48 + 1;
                 cout << "*" << lotteryBall << "*";
    }
 
    cin.get();
 
    return 0;
}
#include <iostream>

using namespace std; 

int main()
{
    srand(time(NULL));
    
    unsigned int lotteryBall;
    
    for(int i = 0; i <=7; ++i)
    {
            lotteryBall = rand() % 48 + 1;
            
            cout << lotteryBall << " ";
            
            if(i == 7)
                 lotteryBall = rand() % 48 + 1;
                 cout << "*" << lotteryBall << "*";
    }
    
    cin.get();
    
    return 0;
}

just added 1 more line

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Re: Stopping same number from appearing twice?

Jun 21st, 2008

That wont work, you fergot to add curly brackets for the if statement.

Last edited by William Hemsworth; Jun 21st, 2008 at 9:25 am.

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Join Date: Jun 2008

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Re: Stopping same number from appearing twice?

Jun 21st, 2008

how can i edit my post?

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Re: Stopping same number from appearing twice?

Jun 21st, 2008

You can only edit your post within 30 minutes of posting it, you will just have to repost it with the correct changes.

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salman213

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Re: Stopping same number from appearing twice?

Jun 21st, 2008

Is this right?

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <iostream>
 
using namespace std;
 
int main()
{
    srand(time(NULL));
 
    unsigned int lotteryBall[9];
 
    for(int i = 0; i <=7; ++i)
    {
            lotteryBall[i] = rand() % 48 + 1;
 
            cout << lotteryBall[i] << " ";
 
            if(i == 7)
{          do {
lotteryBall[i+1] = rand() % 48 + 1;} 
while ( 
(lotteryBall[i+1]==lotteryBall[0])|| 
(lotteryBall[i+1]==lotteryBall[1])|| 
(lotteryBall[i+1]==lotteryBall[2])||
(lotteryBall[i+1]==lotteryBall[3])||
(lotteryBall[i+1]==lotteryBall[4])|| 
(lotteryBall[i+1]==lotteryBall[5])||
(lotteryBall[i+1]==lotteryBall[6])||
(lotteryBall[i+1]==lotteryBall[7]));
 
                 cout << "*" << lotteryBall[i+1] << "*"; }
          }
 
    cin.get();
 
    return 0;
}
#include <iostream>

using namespace std;

int main()
{
    srand(time(NULL));
    
    unsigned int lotteryBall[9];
    
    for(int i = 0; i <=7; ++i)
    {
            lotteryBall[i] = rand() % 48 + 1;
            
            cout << lotteryBall[i] << " ";
            
            if(i == 7)
{          do {
lotteryBall[i+1] = rand() % 48 + 1;} 
while ( 
(lotteryBall[i+1]==lotteryBall[0])|| 
(lotteryBall[i+1]==lotteryBall[1])|| 
(lotteryBall[i+1]==lotteryBall[2])||
(lotteryBall[i+1]==lotteryBall[3])||
(lotteryBall[i+1]==lotteryBall[4])|| 
(lotteryBall[i+1]==lotteryBall[5])||
(lotteryBall[i+1]==lotteryBall[6])||
(lotteryBall[i+1]==lotteryBall[7]));

                 cout << "*" << lotteryBall[i+1] << "*"; }
          }
    
    cin.get();
    
    return 0;
}

Probably much more efficient way that it can be done

Last edited by salman213; Jun 21st, 2008 at 3:29 pm.

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Re: Stopping same number from appearing twice?

Jun 21st, 2008

yep.. try learning loops salman

Last edited by William Hemsworth; Jun 21st, 2008 at 3:28 pm.

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salman213

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Re: Stopping same number from appearing twice?

Jun 21st, 2008

would this be better or worse

???

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <iostream>
 
using namespace std;
 
int check (unsigned int checkvariable[]);
 
int main()
{
    srand(time(NULL));
 
    unsigned int lotteryBall[9];
 
    for(int i = 0; i <=7; ++i)
{
            lotteryBall[i] = rand() % 48 + 1;
 
            cout << lotteryBall[i] << " ";
 
            if(i == 7)
  {
        do {
            lotteryBall[i+1] = rand() % 48 + 1; 
            }while (check(lotteryBall));
  cout << "*" << lotteryBall[i+1] << "*"; 
  }
 
 }
 
    cin.get();
 
    return 0;
}
 
int check (  unsigned int checkvariable[])
{
    for(int a=0;a<=7;++a)
    {
            if (checkvariable[a]==checkvariable[8])
            {return true;
             break;}
             else if (a==7)
             return false;
    }
 
}
#include <iostream>

using namespace std;

int check (unsigned int checkvariable[]);

int main()
{
    srand(time(NULL));
    
    unsigned int lotteryBall[9];
    
    for(int i = 0; i <=7; ++i)
{
            lotteryBall[i] = rand() % 48 + 1;
            
            cout << lotteryBall[i] << " ";
            
            if(i == 7)
  {
        do {
            lotteryBall[i+1] = rand() % 48 + 1; 
            }while (check(lotteryBall));
  cout << "*" << lotteryBall[i+1] << "*"; 
  }
 
 }
    
    cin.get();
    
    return 0;
}

int check (  unsigned int checkvariable[])
{
    for(int a=0;a<=7;++a)
    {
            if (checkvariable[a]==checkvariable[8])
            {return true;
             break;}
             else if (a==7)
             return false;
    }
    
}