skipping input?

Hello guys,

I'm writing a simple tic-tac-toe game just to get some practice with function (for those that read my previous post), and I have encounterd a problem which I've been trying to solve for sometime.

The problem is that if an invalid position has been entered and the lop goes back to the prompt again and a new CORRECT position has been entered it simply says it is wrong again.

Below I'm posting the two functions that handle that process.If anyone could help I would greaty appreciate it!

and by the way I don't know how to use arrays therefore it is all functions.

axon

Code:

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//function switching the coordinates to the global vars
int switchCoordinatesToPosition(char letterPosition, int numberPosition, int&badMove)
{
        if( (letterPosition == 'A') && (numberPosition == 1) )
        {
                if(p1 != ' ') {badMove = -1;}
                else{ return 1; }
        }
        else if( (letterPosition == 'A') && (numberPosition == 2) )
        {
                if(p2 != ' ') {badMove = -1;}
                else{ return 2; }
        }
        else if( (letterPosition == 'A') && (numberPosition == 3) )
        {
                if(p3 != ' ') {badMove = -1;}
                else{ return 3; }
        }
        else if( (letterPosition == 'B') && (numberPosition == 1) )
        {
                if(p4 != ' ') {badMove = -1;}
                else{ return 4; }
        }
        else if( (letterPosition == 'B') && (numberPosition == 2) )
        {
                if(p5 != ' ') { badMove = -1;}
                else{ return 5; }
        }
        else if( (letterPosition == 'B') && (numberPosition == 3) )
        {
                if(p6 != ' ') { badMove = -1;}
                else{ return 6; }
        }
        else if( (letterPosition == 'C') && (numberPosition == 1) )
        {
                if(p7 != ' ') {badMove = -1;}
                else{ return 7; }
        }
        else if( (letterPosition == 'C') && (numberPosition == 2) )
        {
                if(p8 != ' ') { badMove = -1;}
                else{ return 8; }
        }
        else if( (letterPosition == 'C') && (numberPosition == 3) )
        {
                if(p9 != ' ') { badMove = -1;}
                else{ return 9; }
        }
        else { cout << "\nInvalid command...exiting!"; exit(-1);}        //default escape

}

//=================================================================================

        //function displaying the 'to move' prompt
void displayMovePrompt(char& playerValue, char& letterPosition, int& numberPosition,
                                          int& positionNumberOnBoard, int badMove)
{
        do
        {
                switch(playerValue){
                        case 'X': cout << "\n\nPlayer X type in a move position: ";
                                break;
                        case 'O': cout << "\n\nPlayer O type in a move position: ";
                                break;
                }
                cin >> letterPosition >> numberPosition;
       
                letterPosition = toupper(letterPosition);        //convert to CAPS

                                //switch to position number
                positionNumberOnBoard = switchCoordinatesToPosition(letterPosition, numberPosition, badMove);

                                //check for bad imput
                if(badMove == -1)
                {
                        cout << "That is an invalid move!";
                        badMove = -1;
                }
        }
        while(badMove == -1);
}

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I guess I'll aswer myself then:

It works perfectly well when I initialized badMove to equal one inside the do statements.

Can anyone tell me exactlywhy this happens?

thanks

axon

attach the whole cpp file.

Quote:

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Originally posted by RoD
attach the whole cpp file.

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I figured it out, but here is the attachments of the whole cpp file....warning...its still in development.

axon

Code:

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/*
        Program:        Simple tic-tac-toe game
        Date:                02/21/03
*/


#include <iostream>
#include <cctype>
#include <cstdlib>
using namespace std;

        //declaring global variables for the positions on the board
char p1, p2, p3, p4, p5, p6, p7, p8, p9;

        //function displaying the game instructions
void displayInstructions()
{
        cout << "\tWelcome To TicTacToe!!\n\n"
                << "Play against another player or the computer,\n"
                << "    by choosing from the menu below.\n\n"
                << "Enter positions as a letter and number.\n"
                << "\t    ENJOY!!\n\n\n";
}

void displayMenu(int& menuOption)
{
        cout << "Choose from the following options:\n"
                << "    1. Two Player Game\n"
                << "    2. Single Player as 'X'\n"
                << "    3. Single Player as 'O'\n"
                << "Selection: ";
        cin >> menuOption;

        if(menuOption == 1)
                {cout << "\n\n  You chose a Single Player Game!\n\n";}
        else if(menuOption == 2)
                {cout << "\n\n  You chose to play against the computer as 'X'\n\n";}
        else if(menuOption == 3)
                {cout << "\n\n  You chose to play against the computer as 'O'\n\n";}
}

//================================================================================
        //function displaying the game board
void displayBoard()
{
        cout << "\n\n"
                << "\t    1  2  3 \n"
                << "\t A  "<<p1<<" | "<<p2<<" | "<<p3<<" \n"
                << "\t  ----------- \n"
                << "\t B  "<<p4<<" | "<<p5<<" | "<<p6<<"  \n"
                << "\t  ----------- \n"
                << "\t C  "<<p7<<" | "<<p8<<" | "<<p9<<"  \n\n";
        cout << endl;
}



//================================================================================
        //function switching the coordinates to the global vars
int switchCoordinatesToPosition(char letterPosition, int numberPosition, int&badMove)
{
        if( (letterPosition == 'A') && (numberPosition == 1) )
        {
                if(p1 != ' ') {badMove = -1;}
                else{ return 1; }
        }
        else if( (letterPosition == 'A') && (numberPosition == 2) )
        {
                if(p2 != ' ') {badMove = -1;}
                else{ return 2; }
        }
        else if( (letterPosition == 'A') && (numberPosition == 3) )
        {
                if(p3 != ' ') {badMove = -1;}
                else{ return 3; }
        }
        else if( (letterPosition == 'B') && (numberPosition == 1) )
        {
                if(p4 != ' ') {badMove = -1;}
                else{ return 4; }
        }
        else if( (letterPosition == 'B') && (numberPosition == 2) )
        {
                if(p5 != ' ') { badMove = -1;}
                else{ return 5; }
        }
        else if( (letterPosition == 'B') && (numberPosition == 3) )
        {
                if(p6 != ' ') { badMove = -1;}
                else{ return 6; }
        }
        else if( (letterPosition == 'C') && (numberPosition == 1) )
        {
                if(p7 != ' ') {badMove = -1;}
                else{ return 7; }
        }
        else if( (letterPosition == 'C') && (numberPosition == 2) )
        {
                if(p8 != ' ') { badMove = -1;}
                else{ return 8; }
        }
        else if( (letterPosition == 'C') && (numberPosition == 3) )
        {
                if(p9 != ' ') { badMove = -1;}
                else{ return 9; }
        }
        else { cout << "\nInvalid command...exiting!"; exit(-1);}        //default escape

}

//=================================================================================

        //function displaying the 'to move' prompt
void displayMovePrompt(char& playerValue, char& letterPosition, int& numberPosition,
                                          int& positionNumberOnBoard, int badMove)
{
       
       
        do
        {
                badMove=1;               
                switch(playerValue){
                        case 'X': cout << "\n\nPlayer X type in a move position: ";
                                break;
                        case 'O': cout << "\n\nPlayer O type in a move position: ";
                                break;
                }
                cin >> letterPosition >> numberPosition;
       
                letterPosition = toupper(letterPosition);        //convert to CAPS

                                //switch to position number
                positionNumberOnBoard = switchCoordinatesToPosition(letterPosition, numberPosition, badMove);

                                //check for bad imput
                if(badMove == -1)
                {
                        cout << "That is an invalid move!";
                        badMove = -1;
                }
        }
        while(badMove == -1);
}

//================================================================================
        //function making the move
void makeTheMove(int positionNumberOnBoard, char playerValue)
{
        switch(positionNumberOnBoard) {
                case 1: p1 = playerValue; break;
                case 2: p2 = playerValue; break;
                case 3: p3 = playerValue; break;
                case 4: p4 = playerValue; break;
                case 5: p5 = playerValue; break;
                case 6: p6 = playerValue; break;
                case 7: p7 = playerValue; break;
                case 8: p8 = playerValue; break;
                case 9: p9 = playerValue; break;
                default: cout << "Error !MaThMo!\n"; exit(-1); break;
        }

}

//=================================================================================
       

int main()
{
        p1=p2=p3=p4=p5=p6=p7=p8=p9=' ';                //setting the globals to " "

        bool notDone = true;

        char playerValue = 'X';                //setting the player value to X, as X starts
                                                                //the game

        char letterPosition;                //value of the letter coordinate
        int numberPosition;                        //value of the number coordinate
        int positionNumberOnBoard;
        int menuOption;                                //value for the beginning menu
        int badMove;
       

        displayInstructions();                //displaying instructions
        displayMenu(menuOption);        //displaying the menu
        displayBoard();

        while(notDone)
        {
                if(menuOption == 1)
                {
                        displayMovePrompt(playerValue, letterPosition, numberPosition,
                                                          positionNumberOnBoard, badMove); //displaying which player's move
               
                        makeTheMove(positionNumberOnBoard, playerValue);

                        displayBoard();
                       
                        //switchPlayers();
                       
                        //checkForMill();

                        //areWeDone();
                }

        }

        return 0;
}

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