'Random' Question

[BlahBlah]

Hi,

I am wondering if you can ,after making a random number, take away that number from the random generator so you won't get it again the next time you make a random number. I am using srand.

For example: x=rand()%10+1 //say for example this makes x = 3

when I do this again I want it to not make another 3.

Thank you in advance!

[Zaita]

Not in the way you are thinking.

But lets say you wanted to draw a lottery, numbers 1-10. Each number can only appear once. You'd do.

  vector<int> vBallList;

  for (int i = 0; i < 10; ++i)
   vBallList.push_back( (i+1) ); // numbers 1-10.

  srand(time(NULL));

  for (int i = 0; i < 10; ++i) {
   int no = rand() % (10-i);
   cout << "Number was: " << vBallList[no] << endl;
   // Remove Picked Number
   vBallList.erase (vBallList.begin()+no);
  }

Haven't tested, or compiled that code. So take is as pseudo-code. Thats the theory of how I'd do it.

Edit: Whoa. It worked first time lol. Scary

[BlahBlah]

It worked!

Thank you, Zaita!

This also taught me what vectors were and how to use them.

[Zaita]

No worries :)
Vectors are good to know, just good C++ STL if you wanna learn them better.

[BlahBlah]

Yeah, I was trying to do it with an array (which I eventually got it to work) ,but using vectors was so much easier.