how to reset rand() function c++

Question

Good afternoon. I'm working on a quiz which contains four buttons. They contain a randomly selected line of text from a text file. The problem begins when I call 4 integers with the rand() function, which picks numbers from 1-5. Knowing that the rand() function can pick the same numbers, I code this:

if (random4 == random1 || random4 == random2 || random4 == random3) {
  if (random4 == 5) {
    while (random4 == random1 && random4 == random2 && random4 == random3 ||
           random4 != 5) {
      random4--;
    }
    return Button4Making();
  } else {
    while (random4 == random1 && random4 == random2 && random4 == random3) {
      random4++;
    }
    return Button4Making();
  }
}

But now my program works fine but crashes a lot of time. I'm assuming that I need to put a limit or something like that, but I don't know how to do it.

functions :

void game_frame::Button1Making() {
  srand(time(NULL));
  int bla = 0;

  string rading;

  ifstream object(
      "C:\\Users\\Dzemail\\OneDrive\\Desktop\\database\\odgovori.dat");

  while (bla != random1 && getline(object, rading)) {
    ++bla;
  }
  if (bla == random1) {
    button1 = new wxButton(main_panel1, wxID_ANY, rading, wxPoint(10, 10),
                           wxSize(150, 50));
  } else {
    button1 = new wxButton(main_panel1, wxID_ANY, "Error", wxPoint(10, 10),
                           wxSize(150, 50));
  }
}
void game_frame::Button2Making() {
  srand(time(NULL));
  int bla = 0;
  if (random2 == random3 || random2 == random4 || random2 == random1) {
    if (random2 == 5) {
      while (random2 == random1 && random2 == random4 && random2 == random3) {
        random2--;
      }
      return Button2Making();
    } else {
      while (random2 == random1 && random2 == random4 && random2 == random3 ||
             random2 != 5) {
        random2++;
      }
      return Button2Making();
    }
  } else {
    string rading;

    ifstream object(
        "C:\\Users\\Dzemail\\OneDrive\\Desktop\\database\\odgovori.dat");

    while (bla != random2 && getline(object, rading)) {
      ++bla;
    }
    if (bla == random2) {
      button2 = new wxButton(main_panel1, wxID_ANY, rading, wxPoint(200, 10),
                             wxSize(150, 50));
    } else {
      button2 = new wxButton(main_panel1, wxID_ANY, "Error", wxPoint(200, 10),
                             wxSize(150, 50));
    }
  }
}
void game_frame::Button3Making() {
  srand(time(NULL));
  int bla = 0;

  string rading;

  ifstream object(
      "C:\\Users\\Dzemail\\OneDrive\\Desktop\\database\\odgovori.dat");

  while (bla != random3 && getline(object, rading)) {
    ++bla;
  }
  if (bla == random3) {
    button3 = new wxButton(main_panel1, wxID_ANY, rading, wxPoint(400, 10),
                           wxSize(150, 50));
  } else {
    button3 = new wxButton(main_panel1, wxID_ANY, "Error", wxPoint(400, 10),
                           wxSize(150, 50));
  }
}
void game_frame::Button4Making() {
  srand(time(NULL));
  int bla = 0;
  if (random4 == random1 || random4 == random2 || random4 == random3) {
    if (random4 == 5) {
      while (random4 == random1 && random4 == random2 && random4 == random3 ||
             random4 != 5) {
        random4--;
      }
      return Button4Making();
    } else {
      while (random4 == random1 && random4 == random2 && random4 == random3) {
        random4++;
      }
      return Button4Making();
    }

  } else {
    string rading;

    ifstream object(
        "C:\\Users\\Dzemail\\OneDrive\\Desktop\\database\\odgovori.dat");

    while (bla != random4 && getline(object, rading)) {
      ++bla;
    }
    if (bla == random4) {
      button4 = new wxButton(main_panel1, wxID_ANY, rading, wxPoint(600, 10),
                             wxSize(150, 50));
    } else {
      button4 = new wxButton(main_panel1, wxID_ANY, "Error", wxPoint(600, 10),
                             wxSize(150, 50));
    }
  }
}

Answer 1

It sounds like you want a random selection of items from a list, but without repeats. An easy way to do this is to shuffle a list and then read out the items from the shuffled list. This page describes an approach for doing this: https://www.cplusplus.com/forum/general/207328/

In your case, you can create a list with the integers in order like [1, 2, 3, 4] and then shuffle the list, giving you some permutation, e.g. [2, 4, 1, 3]. This ensures you don't have repeats.