Forum: luffar-schack

//tic-tac-toe
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
 
using namespace std;
 
//global constants
const char X = ''X'';
const char O = ''O'';
const char EMPTY = '' '';
const char TIE = ''T'';
const char NO_ONE = ''N'';
 
//functions prototype
void instructions();
char asYesNo(string question);
int askNumber(string question, int high, int low = 0);
char humanPiece();
char opponent(char piece);
void displayBoard(const vector<char>& board);
char winner(const vector<char>& board);
bool isLegal(const vector<char>& board, int move);
int humanMove(const vector<char>& board, char human); 
int computerMove(vector<char> board, char computer);
void announceWinner(char winner, char computer, char human);
 
 
int main()
{
     int move;
     const int NUM_SQUARES = 9;
     vector<char> board(NUM_SQUARES, EMPTY);
 
     instructions();
     char human = humanPiece();
     char computer = opponent(human);
     char turn = X;
     displayBoard(board);
 
     while (winner(board) ==  NO_ONE)
     {
           if (turn == human)
           {
                    move = humanMove(board, human);
                    board[move] = human;
           }
           else
           {
                    move = computerMove(board, computer);
                    board[move] = computer;
           }
           displayBoard(board);
           turn = opponent(turn);
     }
 
     announceWinner(winner(board), computer, human);
 
     cin.get();
     return 0;    
}
 
void instructions()
{
     cout << "Welcome to the ultimate man VS machine showdown: tic-tac-toe!!.n";
     cout << "Where human brain is pit against silicon processornn";
 
     cout << "Make your move by entering a number, 0-8. The numbern";
     cout << "corresponds to the desired board position, as illustrated:nn";
 
     cout << "       0 | 1 | 2n";
     cout << "       ---------n";
     cout << "       3 | 4 | 5n";
     cout << "       ---------n";
     cout << "       6 | 7 | 8nn";
 
     cout << "Prepare yourself, human, the battle is about to begin.nn";
}
 
char askYesNo(string question)
{
     char response;
     do
     {
          cout << question << " (y/n): ";
          cin >> response;
     } while (response != ''y'' && response != ''n'');
 
     return response;
}
 
 
int askNumber(string question, int high, int low)
{
    int number;
    do
    {
        cout << question << " (" << low << " - " << high << "): ";
        cin >> number;    
    }while (number > high || number < low);
 
    return number;
}
 
 
char humanPiece()
{
     char go_first = askYesNo("Do you require the first move?");
     if (go_first == ''y'')
     {
          cout << "nThen take the first move you will need it.n";
          return X;
     }
     else
     {
         cout << "nYour bravery will be your undoing... I will go first.n";
         return 0;
     }
}
 
 
char opponent(char piece)
{
     if (piece == X)
         return 0;
     else
         return X;          
}
 
 
void displayBoard(const vector<char>& board)
{
     cout << "nt" << board[0] << " | " << board[1] << " | " << board[2];
     cout << "nt" << "----------";
     cout << "nt" << board[3] << " | " << board[4] << " | " << board[5];
     cout << "nt" << "----------";
     cout << "nt" << board[6] << " | " << board[7] << " | " << board[8];
     cout << "nn";
}
 
 
char winner(const vector<char>& board)
{
     //all possible winning rows
     const int WINNING_ROWS[8][3]={ {0, 1, 2},
                                    {3, 4, 5},
                                    {6, 7, 8},
                                    {0, 3, 6},
                                    {1, 4, 7},
                                    {2, 5, 8},
                                    {0, 4, 8},
                                    {2, 4, 6} };
 
     const int TOTAL_ROWS = 8;
 
     //if any row has three values that are the same(and not empty).
     //then we have a winner
     for(int row = 0; row < TOTAL_ROWS; ++row)
     {
          if ( (board[WINNING_ROWS[row][0]] != EMPTY ) &&
               (board[WINNING_ROWS[row][0]] == board[WINNING_ROWS[row][1]]) &&
               (board[WINNING_ROWS[row][1]] == board[WINNING_ROWS[row][2]]) )
          {
              return board[WINNING_ROWS[row][0]];                                 
          }
 
           //since  nobody has won, check for a tie(no empty squares left)
           if (count(board.begin(), board.end(), EMPTY) == 0)
           return TIE;  
 
           //since noone has won and it is not a tie the game isn''t over
           return NO_ONE;
     }    
 
}
 
 
inline bool isLegal(const vector<char>& board, int move)
{
     return (board[move] == EMPTY);
}
 
 
int humanMove(const vector<char>& board, char human)
{
    int move = askNumber("Where will you move?", (board.size() - 1));
    while (!isLegal(board, move))
    {
          cout << "The square is already occupied, foolish man.n";
          move = askNumber("Where will you move?", (board.size() - 1));
    }
    cout << "Fine...n";
    return move;
}
 
 
int computerMove(vector<char> board, char computer)
{