Ad:

C++ Discussion Thread
Unsolved
Views: 1140

Page 1
2
Next

You are currently viewing page 1 of this multi-page discussion thread

Jun 21st, 2008

Stopping same number from appearing twice?

Expand Post »

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..

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.

Black Magic

Reputation Points: 25

Solved Threads: 4

Junior Poster

Offline

177 posts
since Apr 2008

Permalink

Jun 21st, 2008

Re: Stopping same number from appearing twice?

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.

William Hemsworth

Reputation Points: 1429

Solved Threads: 129

Posting Virtuoso

Offline

1,542 posts
since Mar 2008

Permalink

Jun 21st, 2008

Re: Stopping same number from appearing twice?

I've modified the script a bit

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

Tigran

Reputation Points: 24

Solved Threads: 8

Junior Poster in Training

Offline

90 posts
since Jun 2008

Permalink

Jun 21st, 2008

Re: Stopping same number from appearing twice?

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.

William Hemsworth

Reputation Points: 1429

Solved Threads: 129

Posting Virtuoso

Offline

1,542 posts
since Mar 2008

Permalink

Jun 21st, 2008

Re: Stopping same number from appearing twice?

how can i edit my post?

Tigran

Reputation Points: 24

Solved Threads: 8

Junior Poster in Training

Offline

90 posts
since Jun 2008

Permalink

Jun 21st, 2008

Re: Stopping same number from appearing twice?

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

William Hemsworth

Reputation Points: 1429

Solved Threads: 129

Posting Virtuoso

Offline

1,542 posts
since Mar 2008

Permalink

Jun 21st, 2008

Re: Stopping same number from appearing twice?

Is this right?

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.

salman213

Reputation Points: 10

Solved Threads: 0

Light Poster

Offline

32 posts
since Jun 2008

Permalink

Jun 21st, 2008

Re: Stopping same number from appearing twice?

yep.. try learning loops salman

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

William Hemsworth

Reputation Points: 1429

Solved Threads: 129

Posting Virtuoso

Offline

1,542 posts
since Mar 2008

Permalink

Jun 21st, 2008

Re: Stopping same number from appearing twice?

would this be better or worse

???

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;
    }
    
}

salman213

Reputation Points: 10

Solved Threads: 0

Light Poster

Offline

32 posts
since Jun 2008

Permalink

Jun 21st, 2008

Re: Stopping same number from appearing twice?

I thought you needed to #include <cstdlib> in order to use the rand() function...?

Ellisande

Reputation Points: 10

Solved Threads: 2

Junior Poster in Training

Offline

53 posts
since Jun 2008

Page 1
2
Next

This thread is more than three months old

No one has posted to this discussion for at least three months. Please let old threads die and do not reply to them unless you feel you have something new and valuable to contribute that absolutely must be added to make the discussion complete. Otherwise, please start a new thread in this forum instead.

Previous Thread in C++ Forum Timeline: Use of getc()/putc() for reading/writing chars, floats, etc. from binary files?

Next Thread in C++ Forum Timeline: how to make system() work in DOS Box

DaniWeb Message

Cancel Changes

User Name
Password