COMP 1917 Computing 1
Session 2, 2016

Lab Solutions - Week 5

Note: This code should be appropriately commented.

1. #include 
   
   #define FALSE    0
   #define TRUE     1
   
   #define SIZE     3
   #define NONE    -1
   #define NOUGHTS  0
   #define CROSSES  1
   #define EMPTY    2
   
   void  scanBoard( int board[SIZE][SIZE] );
   void printBoard( int board[SIZE][SIZE] );
   int   getWinner( int board[SIZE][SIZE] );
   
   int main( void )
   {
      int board[SIZE][SIZE];
      int winner;
   
      printf("Please enter the board:\n");
      scanBoard( board );
      
      printf("Here is the board:\n");
      printBoard( board );
   
      //Find and print the winner
      winner = getWinner( board );
      if( winner == NONE ) {
        printf("No Winner\n");
      }
      else if( winner == NOUGHTS ) {
        printf("Noughts Win\n");
      }
      else {
        printf("Crosses Win\n");
      }    
   
      return 0;
   }
   
   void scanBoard( int board[SIZE][SIZE] )
   {
     int r,c;
     for( r=0; r < SIZE; r++ ) {
       for( c=0; c < SIZE; c++ ) {
         scanf("%d",&board[r][c]);
       }
     }
   }
   
   void printBoard( int board[SIZE][SIZE] )
   {
     int r,c;
     for( r=0; r < SIZE; r++ ) {
       for( c=0; c < SIZE; c++ ) {
         if( board[r][c] == NOUGHTS ) {
           printf(" O");
         }
         else if( board[r][c] == CROSSES ) {
           printf(" X");
         }
         else {
           printf(" .");
         }
       }
       printf("\n");
     }
     printf("\n");
   }
   
   int getWinner( int board[SIZE][SIZE] )
   {
     int gameOver;
     int winner = NONE;
     int r,c;
   
     // check rows
     for( r = 0; r < SIZE && winner == NONE; r++ ) {
       gameOver = TRUE;
       for( c = 0; c < SIZE-1; c++ ) {
         if(   board[r][c] == EMPTY
   	 || board[r][c] != board[r][c+1]) {
           gameOver = FALSE;
         }
       }
       if( gameOver ) {
         winner = board[r][0];
       }
     }
     // check columns
     for( c = 0; c < SIZE && winner == NONE; c++ ) {
       gameOver = TRUE;
       for( r = 0; r < SIZE-1; r++ ) {
         if(   board[r][c] == EMPTY
   	 || board[r][c] != board[r+1][c]) {
           gameOver = FALSE;
         }
       }
       if( gameOver ) {
         winner = board[0][c];
       }
     }
     // check forward diagonal
     if( winner == NONE && board[0][0] != EMPTY ) {
       gameOver = TRUE;
       for( r = 0; r < SIZE-1; r++ ) {
         if( board[r][r] != board[r+1][r+1] ) {
           gameOver = FALSE;
         }
       }
       if( gameOver ) {
         winner = board[0][0];
       }
     }
     // check backward diagonal
     if( winner == NONE && board[0][SIZE-1] != EMPTY ) {
       gameOver = TRUE;
       for( r = 0; r < SIZE-1; r++ ) {
         if( board[r][SIZE-1-r] != board[r+1][SIZE-2-r]) {
           gameOver = FALSE;
         }
       }
       if( gameOver ) {
         winner = board[0][SIZE-1];
       }
     }
   
     return winner;
   }