井字游戏 - 无效输入后如何不打印结果答案

【问题标题】：Tic Tac Toe game - How to not have results print after invalid entry井字游戏 - 无效输入后如何不打印结果
【发布时间】：2014-03-27 05:41:13
【问题描述】：

好的，所以现在当我尝试确定要再次玩的有效输入时，它会在显示无效输入后立即再次显示游戏结果，然后要求用户再次输入 "y" 或 "n" 。我上传了一张图片给你看。我一辈子都想不通。

图片如下： http://imgur.com/SRsMo4P

// GAME OVER
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      while (bGameOver)
      {
            // Display game board - PRINT
            for (int i = 0; i<ROW; ++i)
            {
                cout << " " << board[i][0] << " | " << board[i][1] << " | " << board[i][2] << endl;
                if (i==0 || i==1)
                {
                    cout << " - + - + -" << endl;
                }
            }

            // Player wins - OUTPUT
            if(bWinGame)
            {
                cout << endl;
                cout << " Player "<< playerTurn << " wins! HOORAH! " << endl << endl;
                cout << " Written by: Karolina Sabat - CPSC 1103 - Section: S11" << endl << endl;
            }

            // Play again - OUTPUT & USER INPUT
            //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            // VARIABLES
            char again;         // Play again = "Y" or "N"
            cout << endl;
            cout << " Want to play again? ( Y / N )" << endl << endl;
            cout << " "; cin >> again; cout << endl;

            // Play again - if YES        
            if (again == 'y' || again == 'Y')
            {
                bGameOver=false;        // Reset game state
                bWinGame=true;          // Reset assumption

                board[0][0] = '*';      // Rest game board - Array
                board[0][1] = '*';
                board[0][2] = '*';
                board[1][0] = '*';
                board[1][1] = '*';
                board[1][2] = '*';
                board[2][0] = '*';
                board[2][1] = '*';
                board[2][2] = '*';
            }

            // Play again - if NO
            else if (again == 'n' || again == 'N')
            {
                cout << " Awe oh well, thanks for playing. " << endl << endl;
                cout << " Written by: Karolina Sabat - CPSC 1103 - Section: S11" << endl << endl;
                break;
            }

            else
            {
                cout << " INVALID ENTRY: Please input \"Y\" or \"N\" " << endl << endl;
            }
      }

      // Game play continue
      if (!bGameOver)
      {
          // Switch player turn
          if (playerTurn == 1)
          {
              playerTurn = 2;
          }

          else
          {
              playerTurn = 1;
          }

      }  

}



cout << " "; return 0;
}

【问题讨论】：

标签： c++ arrays loops output

【解决方案1】：

你在这个else声明中没有break：

else
{
    cout << " INVALID ENTRY: Please input \"Y\" or \"N\" " << endl << endl;
}

代码将在没有break 的情况下继续运行，从而导致奇怪的行为。试试这个：

else
{
    cout << " INVALID ENTRY: Please input \"Y\" or \"N\" " << endl << endl;
    break;
}

【讨论】：

【解决方案2】：

将您的输入验证代码放入循环中。如果选择 Y 或 N，则中断循环。

P.S.在代码中添加更正，break; 现在在 wrigth 位置。

// GAME OVER
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      while (bGameOver)
      {
            // Display game board - PRINT
            for (int i = 0; i<ROW; ++i)
            {
                cout << " " << board[i][0] << " | " << board[i][1] << " | " << board[i][2] << endl;
                if (i==0 || i==1)
                {
                    cout << " - + - + -" << endl;
                }
            }

            // Player wins - OUTPUT
            if(bWinGame)
            {
                cout << endl;
                cout << " Player "<< playerTurn << " wins! HOORAH! " << endl << endl;
                cout << " Written by: Karolina Sabat - CPSC 1103 - Section: S11" << endl << endl;
            }

            // Play again - OUTPUT & USER INPUT
            //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            // VARIABLES

            bool bInvalidInput = true;
            while(bInvalidInput)
            {
                    char again;         // Play again = "Y" or "N"
                    cout << endl;
                    cout << " Want to play again? ( Y / N )" << endl << endl;
                    cout << " "; cin >> again; cout << endl;

                    // Play again - if YES        
                    if (again == 'y' || again == 'Y')
                    {
                        bGameOver=false;        // Reset game state
                        bWinGame=true;          // Reset assumption
                        bInvalidInput = false; //stop dialog

                        board[0][0] = '*';      // Rest game board - Array
                        board[0][1] = '*';
                        board[0][2] = '*';
                        board[1][0] = '*';
                        board[1][1] = '*';
                        board[1][2] = '*';
                        board[2][0] = '*';
                        board[2][1] = '*';
                        board[2][2] = '*';
                    }

                    // Play again - if NO
                    else if (again == 'n' || again == 'N')
                    {
                        cout << " Awe oh well, thanks for playing. " << endl << endl;
                        cout << " Written by: Karolina Sabat - CPSC 1103 - Section: S11" << endl << endl;
                        bInvalidInput = false; //stop dialog
                        // break; //need no more
                    }

                    else
                    {
                        cout << " INVALID ENTRY: Please input \"Y\" or \"N\" " << endl << endl;
                    }
            }
            if (bGameOver == true)
            {
                    break; //get here only if bInvalidInput is false and N pressed
            }
      }

      // Game play continue
      if (!bGameOver)
      {
          // Switch player turn
          if (playerTurn == 1)
          {
              playerTurn = 2;
          }

          else
          {
              playerTurn = 1;
          }

      }  

}

【讨论】：

我无法让它工作，它不接受我的输入。
请检查大括号。你有没有在控制台中得到这个字符串" Want to play again? ( Y / N )"

【解决方案3】：

尝试将标记为Display game board - PRINT 和Player wins - OUTPUT 的部分移到while 循环之外（之前）。

【讨论】：

【解决方案4】：

感谢您的建议，但由于某种原因它们无法正常工作，所以我最终这样做了，这是完整的代码：

// FILE: Tic Tac Toe.cpp
// PROGRAMMER: Karolina Sabat   CPSC 1103   Section: S11

// ~~ TWO PLAYER TIC TAC TOE GAME ~~
// Asks the users (player 1, followed by player 2) to select a row and column by 
entering the corresponding row and column number.
// The program will substitute the player's selection with either an "X" or "O".
// A horizontal, vertical or diagonal row of either X's or O's results in a win or 
otherwise game ends in a draw. 
// For subsequent plays, player 1 and player 2 alternate going first. 

#include<iostream>              // For cin, cout
using namespace std;

// MAIN FUNCTION
int main()
{
// VARIABLES
int playerTurn = 1;                         // Player's turn - Player 1
const int ROW=3;                            // Table - Number of rows - For array
const int COL=3;                            // Table - Number of columns - For array
bool bGameOver= false;                      // Game state - True = Game over, False = Continue play
char again;                                 // Play again = "Y" or "N"
char board[ROW][COL] = { {'*', '*', '*'},
                         {'*', '*', '*'},
                         {'*', '*', '*'} }; // Game board - Array


// TITLE
cout << endl;
cout << " TIC TAC TOE" << endl;
cout << " ____________________________________________________" << endl;
cout << " A two player game." << endl;
cout << endl;

// Game state = Continue play - Game is NOT over.
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// Continue play - LOOP
while (!bGameOver)
{
      // Game board - Array - PRINT
      for (int i = 0; i < ROW; ++i)
      {
          cout << " " << board[i][0] <<" | " << board[i][1] <<" | " << board[i][2] << endl;
          if (i==0 || i==1)
          {
                  cout << " - + - + -" << endl;
          }
      }

      // Set player mark ( "X" or "O" )
      // VARIABLES
      char playerMark;
      if (playerTurn == 1)          // Player 1 = "X"
      {
          playerMark = 'X';     
      }
      else
      {
          playerMark = 'O';         // Player 2 = "O"
      }

      // Player move - USER INPUT
      // VARIABLES
      int move_r;                   // Row position - USER INPUT
      int move_c;                   // Column position - USER INPUT
      bool validMove = false;       // Bool ValidMove - Assume false 
      cout << endl;
      cout << " Player " << playerTurn << " , please pick a row and column to place "<< playerMark << "." << endl;
      cout << " Separate the row and column number with a space and press ENTER." << endl;

      while (!validMove) // DETERMINE VALIDITY - Check play move entries
      {
          validMove = true;
          cout << endl;
          cout << " "; cin >> move_r >> move_c; cout << endl;
          // Row 1, Column 1  
          if(move_r == 1 && move_c == 1 && board[0][0] == '*')
          {
              board[0][0] = playerMark;
          }
          // Row 1, Column 2 
          else if(move_r == 1 && move_c == 2 && board[0][1] == '*')
          {
              board[0][1] = playerMark;
          }
          // Row 1, Column 3 
          else if(move_r == 1 && move_c == 3 && board[0][2] == '*')
          {
              board[0][2] = playerMark;
          }
          // Row 2, Column 1 
          else if(move_r == 2 && move_c == 1 && board[1][0] == '*')
          {
              board[1][0] = playerMark;
          }
          // Row 2, Column 2 
          else if(move_r == 2 && move_c == 2 && board[1][1] == '*')
          {
              board[1][1] = playerMark;
          }
          // Row 2, Column 3 
          else if(move_r == 2 && move_c == 3 && board[1][2] == '*')
          {
              board[1][2] = playerMark;
          } 
          // Row 3, Column 1 
          else if(move_r == 3 && move_c == 1 && board[2][0] == '*')
          {
              board[2][0] = playerMark;
          } 
          // Row 3, Column 2 
          else if(move_r == 3 && move_c == 2 && board[2][1] == '*')
          {
              board[2][1] = playerMark;
          }
          // Row 3, Column 3 
          else if(move_r == 3 && move_c == 3 && board[2][2] == '*')
          {
              board[2][2] = playerMark;

          } 

          // INVALID ENTRY
          else 
          {
              cout << " Invalid Move, please try again!" << endl << endl;
              // Will clear characters
              cin.clear();
              cin.ignore(numeric_limits<streamsize>::max(), '\n');
              validMove = false;
          }

      }
      // Check if game over conditions are met
      // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      // If row 0 or column 0 = same playerMark
      if (board[0][0] != '*')
      {
            if (board[0][0] == board[0][1] && board[0][0] == board[0][2])   // Check row 0
            {
                bGameOver=true;
            }
            if (board[0][0] == board[1][0] && board[0][0] == board[2][0])   // Check column 0
            {
                bGameOver=true;
            }
      }

      // If row 1 or column 1 = same playerMark
      if (board[1][1] != '*')
      {

            if(board[1][1] == board[1][0] && board[1][1] == board[1][2])    // Check row 1
            {
                bGameOver=true;
            }

              if(board[1][1] == board[0][1] && board[1][1] == board[2][1])  // Check column 1
            {
                bGameOver=true;
            }

            if(board[1][1] == board[0][0] && board[1][1] == board[2][2])    // Diagonals - Check if 1,1 and 3,3 are equal to 2,2
            {
                bGameOver=true;
            }
            if(board[1][1] == board[2][0] && board[1][1] == board[0][2])    // Diagnonals - Check if 1,3 and 3,1 are equal to 2,2
            {
                bGameOver=true;
            }
      }

      // If row 2 or column 2 = same playerMark
      if (board[2][2] != '*')
      {
            if (board[2][2] == board[2][1] && board[2][2] == board[2][0])   // Check row 2
            {
                bGameOver=true;
            }
            if (board[2][2] == board[1][2] && board[2][2] == board[0][2])   // Check column 2
            {
                bGameOver=true;
            }
      }

      // Check if DRAW
      bool bWinGame=true; // ASSUMPTION - A player won
      if (board[0][0] !='*' && board[0][1] !='*' && board[0][2] !='*' && 
          board[1][0] !='*' && board[1][1] !='*' && board[1][2] !='*' &&
          board[2][0] !='*' && board[2][1] !='*' && board[2][2] !='*' && !bGameOver)
      {
          bGameOver=true;
          bWinGame=false;
          // Tie - OUTPUT
          cout << " Oh, won't you look at that, it's a TIE!"<< endl << endl;
          cout << " Written by: Karolina Sabat - CPSC 1103 - Section: S11" << endl << endl;
      }

      // GAME OVER
      // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      while (bGameOver)
      {
            // Display game board - PRINT
            for (int i = 0; i<ROW; ++i)
            {
                cout << " " << board[i][0] << " | " << board[i][1] << " | " << board[i][2] << endl;
                if (i==0 || i==1)
                {
                    cout << " - + - + -" << endl;
                }
            }

            // Player wins - OUTPUT
            if(bWinGame)
            {
                cout << endl;
                cout << " Player "<< playerTurn << " wins! HOORAH! " << endl << endl;
                cout << " Written by: Karolina Sabat - CPSC 1103 - Section: S11" << endl << endl;
            }

            // Play again - OUTPUT & USER INPUT
            //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            // VARIABLES
            bool bValidInput = false;

            while (bValidInput != true)
            {

                cout << endl;
                cout << " Want to play again? ( Y / N )" << endl << endl;
                cout << " ";
                // Will clear characters
                cin.clear();
                cin.ignore(numeric_limits<streamsize>::max(), '\n');
                cin >> again; cout << endl;

                // Play again - if YES        
                if (again == 'y' || again == 'Y')
                {
                    bValidInput = true;
                    bGameOver=false;        // Reset game state
                    bWinGame=true;          // Reset assumption


                    board[0][0] = '*';      // Rest game board - Array
                    board[0][1] = '*';
                    board[0][2] = '*';
                    board[1][0] = '*';
                    board[1][1] = '*';
                    board[1][2] = '*';
                    board[2][0] = '*';
                    board[2][1] = '*';
                    board[2][2] = '*';
                }

                // Play again - if NO
                else if (again == 'n' || again == 'N')
                {
                    bValidInput = true; // Assumes 
                    cout << " Awe oh well, thanks for playing. " << endl << endl;
                    cout << " Written by: Karolina Sabat - CPSC 1103 - Section: S11" << endl << endl;
                    cout << " "; return 0;
                }

                // Play again - INVALID ENTRY
                else
                {
                    cout << " INVALID ENTRY: Please input \"Y\" or \"N\" " << endl << endl;
                    bValidInput = false;
                }
            }   

      }

      // Game play continue
      if (!bGameOver)
      {
          // Switch player turn
          if (playerTurn == 1)
          {
              playerTurn = 2;
          }

          else
          {
              playerTurn = 1;
          }

      }  

}

// EXIT PROGRAM
 cout << " "; return 0;
}

【讨论】：

其实这并不能完全解决问题，我必须输入两次yes或no，为什么？并且建议的方法 nondefaultname 不起作用。