C++ switch statement

Question

Да, я учился в колледже. Нет, мы еще не изучали массивы или программы более высокого уровня. Мы находимся в главе 4 книги. Хорошо, в соответствии с отзывами моей последней попытки, я думаю, что на этот раз я правильно разместил сообщение. Сожалею!

Здесь код теперь замерзает.

else if (human_turn == false) 
        { 
         switch (num_toothpicks) 
         { 
         case '4': 
          std::cout << "The computer takes 3 toothpicks from the pile.\n"; 
          computer_pick = 3; 
          num_toothpicks = num_toothpicks - computer_pick; 
          std::cout << "There is only one toothpick left in the pile. You lose this game.\n"; 
          human_turn = true; 
          break; 
         case '3': 
          std::cout << "The computer takes 2 toothpicks from the pile.\n"; 
          computer_pick = 2; 
          num_toothpicks = num_toothpicks - computer_pick; 
          std::cout << "There is only one toothpick left in the pile. You lose this game.\n"; 
          human_turn = true; 
          break; 
         case '2': 
          std::cout << "The computer takes 1 toothpick from the pile.\n"; 
          computer_pick = 1; 
          num_toothpicks = num_toothpicks - computer_pick; 
          std::cout << "There is only one toothpick left in the pile.\n"; 
          human_turn = true; 
          break; 
         } 
        } 

Он надлежащим образом исполняет UNLESS, когда пользователю требуется, чтобы компьютер выполнил оператор switch выше.

Полный код:

#include <iostream> 
#include <cstdlib> 
#include <ctime> 


/*~~~~~~~~~~~~~~~~~~~~~~~~~ 
*K 
*created 2/20/16 
*23 Toothpicks Game 
---Allows the user to play a game of 23 against the computer 
~~~~~~~~~~~~~~~~~~~~~~~~~*/ 
int main() 
{ 
    srand(time(NULL)); //seed for random number 

    auto Random_computer_pick = (rand() % 3) + 1; //computer chooses a random number between 1 and 3 
    int user_pick, computer_pick; 
    int game_number = 1; 
    char keep_going; 
    int num_toothpicks = 23; 
    bool human_turn = true; 

    do { 
     std::cout << "23 is a two-player game that begins with a pile of 23 tooth picks.\n" 
      << "Players take turns, withdrawing either 1, 2, or 3 toothpicks at a time.\n" 
      << "The player to withdraw the last toothpick loses the game.\n" 
      << "You will be playing against the computer.\n\n\n\n"; 
     if (game_number % 2 != 0) 
     { 
      do 
      { 
       if (num_toothpicks > 4) 
       { 
        //userpick 
        std::cout << "There are " << num_toothpicks << ". Please choose to pull 1, 2, or 3 toothpicks from the pile.\n"; 
        std::cin >> user_pick; 
        /*Make sure the user picks 1, 2, or 3*/ 
        if (user_pick != 1 && user_pick != 2 && user_pick != 3) 
        { 
         std::cout << "Invalid entry. Please enter 1, 2, or 3.\n"; 
         std::cin >> user_pick; 
        } 
        /*End Make Sure the user picks 1 2 3*/ 
        num_toothpicks = num_toothpicks - user_pick; 
        human_turn = false; 
        std::cout << "There are " << num_toothpicks << " left in the pile.\n\n\n"; 
        //computer pick 
        computer_pick = 4 - user_pick; 
        num_toothpicks = num_toothpicks - computer_pick; 
        human_turn = true; 
        std::cout << "The computer chose " << computer_pick << ". That leaves " << num_toothpicks << ".\n"; 
       } 

       else if ((num_toothpicks <= 4) && (num_toothpicks != 1)) 
       { 
        if (human_turn == true) 
        { 
         std::cout << "There are " << num_toothpicks << ". Please choose to pull 1, 2, or 3 toothpicks from the pile.\n"; 
         std::cin >> user_pick; 
         human_turn = false; 
         /*Make sure the user picks 1, 2, or 3*/ 
         if (user_pick != 1 && user_pick != 2 && user_pick != 3) 
         { 
          std::cout << "Invalid entry. Please enter 1, 2, or 3.\n"; 
          std::cin >> user_pick; 
         } 
         /*End Make Sure the user picks 1 2 3*/ 
         num_toothpicks = num_toothpicks - user_pick; 
         std::cout << "There are " << num_toothpicks << " left in the pile.\n\n\n"; 
        } 
        else if (human_turn == false) 
        { 
         switch (num_toothpicks) 
         { 
         case '4': 
          std::cout << "The computer takes 3 toothpicks from the pile.\n"; 
          computer_pick = 3; 
          num_toothpicks = num_toothpicks - computer_pick; 
          std::cout << "There is only one toothpick left in the pile. You lose this game.\n"; 
          human_turn = true; 
          break; 
         case '3': 
          std::cout << "The computer takes 2 toothpicks from the pile.\n"; 
          computer_pick = 2; 
          num_toothpicks = num_toothpicks - computer_pick; 
          std::cout << "There is only one toothpick left in the pile. You lose this game.\n"; 
          human_turn = true; 
          break; 
         case '2': 
          std::cout << "The computer takes 1 toothpick from the pile.\n"; 
          computer_pick = 1; 
          num_toothpicks = num_toothpicks - computer_pick; 
          std::cout << "There is only one toothpick left in the pile.\n"; 
          human_turn = true; 
          break; 
         } 
        } 
       } 
       else if (num_toothpicks == 1) 
       { 
        if (human_turn == true) 
        { 
         std::cout << "You are stuck with the last toothpick. You lost. Sorry!\n\n"; 
         num_toothpicks--; 
         game_number++; 
        } 
        if (human_turn == false) 
        { 
         std::cout << "The computer was forced to take the last toothpick. The user won the game!\n\n"; 
         num_toothpicks--; 
         game_number++; 
        } 
       } 
      } while (num_toothpicks > 0); 



      std::cout << "Do you wish to play again? Enter Y to continue, or N to close the program.\n"; 
      num_toothpicks = 23; 
      std::cin >> keep_going; 
      std::cout << std::endl; 
      if (keep_going != 'Y' && keep_going != 'y' && keep_going != 'N' && keep_going != 'n') 
      { 
       std::cout << "Invalid entry. Do you wish to play again ? Enter Y to continue, or N to close the program.\n"; 
       std::cin >> keep_going; 
      } 
      if (keep_going == 'N' || keep_going == 'n') 
      { 
       std::cout << "Thanks for playing!\n"; 
       break; 
      } 
     } 
     else if (game_number % 2 == 0) 
     { 
      do 
      { 
       if (num_toothpicks == 23) 
       { 
        std::cout << "23 is a two-player game that begins with a pile of 23 tooth picks.\n" 
         << "Players take turns, withdrawing either 1, 2, or 3 toothpicks at a time.\n" 
         << "The player to withdraw the last toothpick loses the game.\n" 
         << "You will be playing against the computer.\n\n\n\n"; 
        num_toothpicks = num_toothpicks - Random_computer_pick; 
        std::cout << "The computer has chosen to pull " << Random_computer_pick << " from the pile.\n"; 
        std::cout << "That leaves " << num_toothpicks << ".\n\n\n"; 
        human_turn = true; 
       } 
       if (num_toothpicks > 4) 
       { 
        //userpick 
        std::cout << "There are " << num_toothpicks << ". Please choose to pull 1, 2, or 3 toothpicks from the pile.\n"; 
        std::cin >> user_pick; 
        /*Make sure the user picks 1, 2, or 3*/ 
        if (user_pick != 1 && user_pick != 2 && user_pick != 3) 
        { 
         std::cout << "Invalid entry. Please enter 1, 2, or 3.\n"; 
         std::cin >> user_pick; 
        } 
        /*End Make Sure the user picks 1 2 3*/ 
        num_toothpicks = num_toothpicks - user_pick; 
        human_turn = false; 
        std::cout << "There are " << num_toothpicks << " left in the pile.\n\n\n"; 
        //computer pick 
        computer_pick = 4 - user_pick; 
        num_toothpicks = num_toothpicks - computer_pick; 
        human_turn = true; 
        std::cout << "The computer chose " << computer_pick << ". That leaves " << num_toothpicks << ".\n"; 
       } 

       else if ((num_toothpicks <= 4) && (num_toothpicks != 1)) 
       { 
        if (human_turn == true) 
        { 
         std::cout << "There are " << num_toothpicks << ". Please choose to pull 1, 2, or 3 toothpicks from the pile.\n"; 
         std::cin >> user_pick; 
         human_turn = false; 
         /*Make sure the user picks 1, 2, or 3*/ 
         if (user_pick != 1 && user_pick != 2 && user_pick != 3) 
         { 
          std::cout << "Invalid entry. Please enter 1, 2, or 3.\n"; 
          std::cin >> user_pick; 
         } 
         /*End Make Sure the user picks 1 2 3*/ 
         num_toothpicks = num_toothpicks - user_pick; 
         std::cout << "There are " << num_toothpicks << " left in the pile.\n\n\n"; 
        } 
        else if (human_turn == false) 
        { 
         switch (num_toothpicks) 
         { 
         case '4': 
          std::cout << "The computer takes 3 toothpicks from the pile.\n"; 
          computer_pick = 3; 
          num_toothpicks = num_toothpicks - computer_pick; 
          std::cout << "There is only one toothpick left in the pile. You lose this game.\n"; 
          human_turn = true; 
          break; 
         case '3': 
          std::cout << "The computer takes 2 toothpicks from the pile.\n"; 
          computer_pick = 2; 
          num_toothpicks = num_toothpicks - computer_pick; 
          std::cout << "There is only one toothpick left in the pile. You lose this game.\n"; 
          human_turn = true; 
          break; 
         case '2': 
          std::cout << "The computer takes 1 toothpick from the pile.\n"; 
          computer_pick = 1; 
          num_toothpicks = num_toothpicks - computer_pick; 
          std::cout << "There is only one toothpick left in the pile.\n"; 
          human_turn = true; 
          break; 
         } 
        } 
       } 
       else if (num_toothpicks == 1) 
       { 
        if (human_turn == true) 
        { 
         std::cout << "You are stuck with the last toothpick. You lost. Sorry!\n\n"; 
         num_toothpicks--; 
         game_number++; 
        } 
        if (human_turn == false) 
        { 
         std::cout << "The computer was forced to take the last toothpick. The user won the game!\n\n"; 
         num_toothpicks--; 
         game_number++; 
        } 
       } 
      } while (num_toothpicks > 0); 



      std::cout << "Do you wish to play again? Enter Y to continue, or N to close the program.\n"; 
      num_toothpicks = 23; 
      std::cin >> keep_going; 
      std::cout << std::endl; 
      if (keep_going != 'Y' && keep_going != 'y' && keep_going != 'N' && keep_going != 'n') 
      { 
       std::cout << "Invalid entry. Do you wish to play again ? Enter Y to continue, or N to close the program.\n"; 
       std::cin >> keep_going; 
      } 
      if (keep_going == 'N' || keep_going == 'n') 
      { 
       std::cout << "Thanks for playing!\n"; 
       break; 
      } 
     } 
    } 
    while (keep_going != 'N' || keep_going != 'n'); 
system("pause"); 
return 0; 
} 

Answer 1

Вы должны удалить кавычки из значений INT, так что они оцениваются как Интс, а не символы. Кроме того, вам необходимо включить обработку ошибок. После последнего случая в вашем заявлении коммутатора вам необходимо указать случай default, если не выполняются никакие другие условия. Он может выглядеть примерно так:

default: 
    std::cout "Error: unexpected case reached: " + num_toothpicks + "\n"; 
    break; 

Answer 2

Исходный код-переключатель искал символ, а не значение int для каждого случая. добавил значение по умолчанию, чтобы не использовать его для последующего устранения неполадок и предотвращения зависания кода.

Спасибо всем.

  else if (human_turn == false) 
      { 
       switch (num_toothpicks) 
       { 
       case 4: 
        std::cout << "The computer takes 3 toothpicks from the pile.\n"; 
        computer_pick = 3; 
        num_toothpicks = num_toothpicks - computer_pick; 
        std::cout << "There is only one toothpick left in the pile. You lose this game.\n"; 
        human_turn = true; 
        break; 
       case 3: 
        std::cout << "The computer takes 2 toothpicks from the pile.\n"; 
        computer_pick = 2; 
        num_toothpicks = num_toothpicks - computer_pick; 
        std::cout << "There is only one toothpick left in the pile. You lose this game.\n"; 
        human_turn = true; 
        break; 
       case 2: 
        std::cout << "The computer takes 1 toothpick from the pile.\n"; 
        computer_pick = 1; 
        num_toothpicks = num_toothpicks - computer_pick; 
        std::cout << "There is only one toothpick left in the pile.\n"; 
        human_turn = true; 
        break; 
       default: 
        std::cout << "Something's Broken! Fix me!"; 
        break; 
       } 
      }