如何重置rand（）函数c ++

Question

下午好。 我正在做一个包含四个按钮的测验。它们包含从文本文件中随机选择的文本行。当我使用 rand() 函数调用 4 个整数时，问题就开始了，该函数从 1-5。知道 rand() 函数可以选择相同的数字，我编写了以下代码：

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();
  }
}

但现在我的程序运行良好，但崩溃了很多时间。 我假设我需要设置一个限制或类似的东西，但我不知道该怎么做。

功能：

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

听起来您想要从列表中随机选择项目，但没有重复。一个简单的方法是打乱一个列表，然后从打乱的列表中读出项目。此页面描述了执行此操作的方法：https://www.cplusplus.com/forum/general/207328/

在您的情况下，您可以按 [1, 2, 3, 4] 之类的顺序创建一个包含整数的列表，然后将列表打乱，给您一些排列，例如[2、4、1、3]。这样可以确保您没有重复。