From 6d38eb746e86589e3b8fa10ba37d206af5eb7ebf Mon Sep 17 00:00:00 2001 From: Scott Gasch Date: Wed, 1 Jun 2016 19:41:17 -0700 Subject: Initial checking of tic tac toe minimax tutorial code. --- ver0/ttt.c | 329 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 329 insertions(+) create mode 100644 ver0/ttt.c (limited to 'ver0/ttt.c') diff --git a/ver0/ttt.c b/ver0/ttt.c new file mode 100644 index 0000000..779cbe5 --- /dev/null +++ b/ver0/ttt.c @@ -0,0 +1,329 @@ +#include +#include +#include +#include +#include "ttt.h" + +SQUARE g_sComputerPlays = O_MARK; // what side comp plays + +//+---------------------------------------------------------------------------- +// +// Function: SquareContentsToChar +// +// Synopsis: Helper function for DrawBoard +// +// Arguments: IN SQUARE s - a square to return a char to represent +// +// Returns: char - character representing square +// +//+---------------------------------------------------------------------------- +char SquareContentsToChar(IN SQUARE s) +{ + static char c; + switch(s) + { + case X_MARK: + c = 'X'; + break; + case O_MARK: + c = 'O'; + break; + default: + c = '_'; + break; + } + return(c); +} + +//+---------------------------------------------------------------------------- +// +// Function: DrawBoard +// +// Synopsis: Draw the board +// +// Arguments: IN POSITION *p - pointer to a position whose board to draw +// +// Returns: void +// +//+---------------------------------------------------------------------------- +void DrawBoard(IN POSITION *p) +{ + COORD x, y; + + for (y = 0; y < BOARD_SIZE; y++) + { + for (x = 0; x < BOARD_SIZE; x++) + { + printf("%c ", SquareContentsToChar(p->sBoard[y][x])); + } + printf("\n"); + } + printf("\n%c to move.\n", SquareContentsToChar(p->sWhoseTurn)); +} + +//+---------------------------------------------------------------------------- +// +// Function: ClearBoard +// +// Synopsis: Clear the board +// +// Arguments: IN OUT POSITION *p - pointer to position whose board to clear +// +// Returns: void +// +//+---------------------------------------------------------------------------- +void ClearBoard(IN OUT POSITION *p) +{ + memset(p->sBoard, 0, sizeof(p->sBoard)); + p->sWhoseTurn = X_MARK; + p->uNumEmpty = (BOARD_SIZE * BOARD_SIZE); +} + +//+---------------------------------------------------------------------------- +// +// Function: IsLegalMove +// +// Synopsis: Determine if a given move is legal on a given board +// +// Arguments: IN POSITION *p - the board to play the move on +// IN MOVE *m - the move in question +// +// Returns: BOOL - TRUE if it's legal, FALSE otherwise +// +//+---------------------------------------------------------------------------- +BOOL IsLegalMove(IN POSITION *p, IN MOVE *m) +{ + if ((m->cVpos < BOARD_SIZE) && (m->cHpos < BOARD_SIZE)) + { + if (IS_SQUARE_EMPTY(p->sBoard[m->cVpos][m->cHpos])) + { + return(TRUE); + } + } + return(FALSE); +} + +//+---------------------------------------------------------------------------- +// +// Function: GetHumanMove +// +// Synopsis: Ask the human for a move +// +// Arguments: IN POSITION *p - the current board +// OUT MOVE *m - the move the human made; this struct is populated +// as a side-effect of this function. +// +// Returns: void* (populates the move struct) +// +//+---------------------------------------------------------------------------- +void GetHumanMove(IN POSITION *p, OUT MOVE *m) +{ + unsigned int x; + + do + { + printf("Enter your move number: "); + scanf("%u", &x); + + m->cHpos = (x % BOARD_SIZE); + m->cVpos = (x / BOARD_SIZE); + m->sMark = g_sComputerPlays * -1; + } + while(FALSE == IsLegalMove(p, m)); +} + +//+---------------------------------------------------------------------------- +// +// Function: SearchForComputerMove +// +// Synopsis: Use our sophisticated search algorithm to find a computer +// move +// +// Arguments: IN POSITION *p - the current board +// OUT MOVE *m - the move the computer chooses; this move struct +// is populated as a side-effect of this function. +// +// Returns: void* (populates move struct) +// +//+---------------------------------------------------------------------------- +void SearchForComputerMove(IN POSITION *p, OUT MOVE *m) +{ + unsigned int x; + + do + { + x = rand() % (BOARD_SIZE * BOARD_SIZE); + m->cHpos = (x % BOARD_SIZE); + m->cVpos = (x / BOARD_SIZE); + m->sMark = g_sComputerPlays; + } + while(FALSE == IsLegalMove(p, m)); +} + +//+---------------------------------------------------------------------------- +// +// Function: MakeMove +// +// Synopsis: Make a move on a board +// +// Arguments: IN OUT POSITION *p - the board +// IN MOVE *m - the move +// +// Returns: void +// +//+---------------------------------------------------------------------------- +void MakeMove(IN OUT POSITION *p, IN MOVE *m) +{ + if (TRUE == IsLegalMove(p, m)) + { + p->sBoard[m->cVpos][m->cHpos] = m->sMark; + p->uNumEmpty--; + p->sWhoseTurn *= -1; + } +} + +//+---------------------------------------------------------------------------- +// +// Function: GameOver +// +// Synopsis: Is the game over? +// +// Arguments: IN POSITION *p - the board +// OUT SQUARE *psWhoWon - who won the game (if it's over) +// +// Returns: TRUE if the game is over. Also sets psWhoWon telling +// which side one if the game is over. +// +// FALSE if the game is not over. +// +//+---------------------------------------------------------------------------- +BOOL GameOver(IN POSITION *p, OUT SQUARE *psWhoWon) +{ + int iSum; + COORD x, y; + + for (x = 0; x < BOARD_SIZE; x++) + { + iSum = 0; + + for (y = 0; y < BOARD_SIZE; y++) + { + iSum += p->sBoard[x][y]; + } + if (abs(iSum) == BOARD_SIZE) goto winner; + } + + for (y = 0; y < BOARD_SIZE; y++) + { + iSum = 0; + + for (x = 0; x < BOARD_SIZE; x++) + { + iSum += p->sBoard[x][y]; + } + if (abs(iSum) == BOARD_SIZE) goto winner; + } + + iSum = 0; + for (x = 0; x < BOARD_SIZE; x++) + { + iSum += p->sBoard[x][x]; + } + if (abs(iSum) == BOARD_SIZE) goto winner; + + iSum = 0; + for (x = 0; x < BOARD_SIZE; x++) + { + iSum += p->sBoard[x][(BOARD_SIZE - 1 - x)]; + } + if (abs(iSum) == BOARD_SIZE) goto winner; + + *psWhoWon = EMPTY; + if (p->uNumEmpty == 0) + { + return(TRUE); + } + else + { + return(FALSE); + } + + winner: + *psWhoWon = (iSum / BOARD_SIZE); + return(TRUE); +} + +//+---------------------------------------------------------------------------- +// +// Function: main +// +// Synopsis: The program entry point and main game loop. +// +// Arguments: void +// +// Returns: int +// +//+---------------------------------------------------------------------------- +int main(void) +{ + POSITION p; + MOVE mv; + SQUARE sResult; + + // + // Randomize: the random numbers returned by rand() will be based on + // the system clock when the program starts up. + // + srand(time(0)); + + // + // Setup the board and draw it once. + // + ClearBoard(&p); + DrawBoard(&p); + + // + // Main game loop + // + do + { + // + // See whose turn it is -- the human's or the computers -- and + // get a move from whoever's turn it is. + // + if (p.sWhoseTurn == g_sComputerPlays) + { + SearchForComputerMove(&p, &mv); + } + else + { + GetHumanMove(&p, &mv); + } + + // + // Make the move on the board and draw the board again. + // + MakeMove(&p, &mv); + DrawBoard(&p); + } + while(FALSE == GameOver(&p, &sResult)); + + // + // If we get here the game is over... see what happened. + // + switch(sResult) + { + case X_MARK: + printf("\nX's win.\n"); + break; + case O_MARK: + printf("\nO's win.\n"); + break; + default: + printf("Tie (what a surprise)\n"); + break; + } + + exit(0); +} + -- cgit v1.3