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HunterVL/Tic-Tac-Toe.ino

Last active February 16, 2017 16:07
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Tic-Tac-Toe.ino
#define compareBoxes(box1, box2, box3) ((board[box1] == board[box2]) && (board[box2] == board[box3]) && (board[box1] != 0)) //Checkes if three items are the same, and makes sure they're not 0's.
#define numberToLetter(x) ((x > 0) ? (x == 1) ? 'X' : 'O' : ' ') //Takes the number and turns it into the letter or space.
int getWinner(int board[9]) {
//Finds winner of game, if there is no winner, returns 0.
int winner = 0;
for (int x = 0; x < 3; x++) {
if (compareBoxes(3*x, 3*x+1, 3*x+2)) { //Chekcs rows.
winner = board[3*x];
break;
} else if (compareBoxes(x, x+3, x+6)) { //Checks columns.
winner = board[x];
break;
} else if (compareBoxes(2*x, 4, 8-2*x) && (x < 2)) { //Checks diagonals. Doesn't check if x == 2.
winner = board[4];
break;
}
}
return winner;
}
bool gameOver(int board[9]){
//Checks if game is over, and announces who won, or if it was a tie.
int properPorts[2][9] = {{2,4,6,13,11,8,19,17,15}, {3,5,7,12,10,9,18,16,14}};
int winner = getWinner(board);
if (winner > 0) {
for (int x = 0; x < 9; x ++) {
digitalWrite(properPorts[winner-1][x], HIGH);
digitalWrite(properPorts[winner % 2][x], LOW);
}
Serial.print(numberToLetter(winner));
Serial.println(" wins!\n");
return true;
}
for (int x = 0; x < 9; x++) {
if (board[x] == 0) return false;
}
for(int x = 2; x < 20; x++) digitalWrite(x, HIGH);
Serial.println("Tie!\n");
return true;
}
int willWin(int board[9], int player) {
//Checks if a given player could win in the next plank.
for (int x = 0; x < 9; x++) {
int tempBoard[9];
memcpy(tempBoard, board, 36);
if (board[x] > 0) continue;
tempBoard[x] = player;
if(getWinner(tempBoard) == player) return x;
}
return -1;
}
int exceptionalCase(int board[9]) {
//Finds bords that are exceptions to how the algorithm works.
int cases[2][9] = {{1,0,0,0,2,0,0,0,1}, {0,1,0,1,2,0,0,0,0}}; //Boards that don't work with algorithm.
int answers[2][4] = {{3,3,3,3}, {2,8,6,0}};
int rotatedBoard[9] = {6,3,0,7,4,1,8,5,2};
int newBoard[9];
int tempBoard[9];
for(int x = 0; x < 9; x++) {
newBoard[x] = board[x];
}
for (int caseIndex = 0; caseIndex < 2; caseIndex++) {
for(int rotation = 0; rotation < 4; rotation++) {
for (int x = 0; x < 9; x++)
tempBoard[x] = newBoard[x];
int match = 0;
//Rotates board so it works with different versions of the same board.
for (int box = 0; box < 9; box++) {
newBoard[box] = tempBoard[rotatedBoard[box]];
}
for (int x = 0; x < 9; x++) {
if (newBoard[x] == cases[caseIndex][x]) match++;
else break;
}
if (match == 9) return answers[caseIndex][rotation];
}
}
return -1;
}
int getSpace(int board[9], int spaces[4]) {
//Gets a random corner or side that's not taken.
bool isSpaceEmpty = false;
int y;
for (int x = 0; x < 4; x++) {
if (board[spaces[x]] == 0) {
isSpaceEmpty = true;
break;
}
}
if (isSpaceEmpty) {
do {
y = random(4);
} while (board[spaces[y]] != 0);
return spaces[y];
}
return -1;
}
void outputBoard(int board[9]) {
int properPorts[2][9] = {{2,4,6,13,11,8,19,17,15}, {3,5,7,12,10,9,18,16,14}};
for(int line = 0; line < 3; line++){
for (int box = 0; box < 3; box++) {
Serial.print(numberToLetter(board[3*line+box]));
Serial.print((box < 2) ? '|' : '\n');
}
Serial.print((line < 2) ? "-----\n" : "\n");
}
for (int port = 0; port < 9; port++) {
if (board[port] != 0) {
digitalWrite(properPorts[board[port]-1][port], HIGH); //Turns on LED on board. Port is different deppending on colour.
}
}
}
int playerMove(int board[9], bool player) {
int play;
char playString;
do {
Serial.print((player) ? "X: " : "O: ");
Serial.flush();
while (!Serial.available());
playString = Serial.readString()[0];
Serial.println(playString);
Serial.println();
play = (int) (playString - '1');
} while ((play < 0) || (play > 8) || (board[play] != 0));
return play;
}
void setup() {
Serial.begin(9600);
Serial.println("1|2|3\n-----\n4|5|6\n-----\n7|8|9\n");
for (int port = 0; port < 20; port++) pinMode(port, OUTPUT);
}
int possibleWinner;
int corners[4] = {0,2,6,8};
int sides[4] = {1,3,5,7};
int isNon;
bool isInvalid;
bool fightingPlayer;
void loop() {
int board[9] = {0,0,0,0,0,0,0,0,0}; //Starts empty board.
do {
Serial.flush();
Serial.print("Jouer contre un joueur (O/N): ");
while (!Serial.available());
isNon = Serial.read();
Serial.println((char) isNon);
if (isNon == 79) fightingPlayer = true;
else if (isNon == 78) fightingPlayer = false;
//else Serial.println("Invalid input");
} while ((isNon != 79) && (isNon != 78));
randomSeed(millis());
while (true) {
//Player X decides what play they'll do.
board[playerMove(board, true)] = 1;
if (fightingPlayer) outputBoard(board);
//Decides whether or not the game continues.
if (gameOver(board) > 0) {
outputBoard(board);
gameOver(board);
delay(2000);
for (int x = 0; x < 20; x++) digitalWrite(x, LOW);
break;
}
//Player O decides which move they'll do.
if (fightingPlayer) board[playerMove(board, false)] = 2;
else {
bool good = false;
for (int x = 2; x > 0; x--){
possibleWinner = willWin(board, x);
if (possibleWinner != -1) {
board[possibleWinner] = 2;
good = true;
break;
}
}
if (good);
else if (board[4] == 0) board[4] = 2; //Middle.
else if (exceptionalCase(board) > -1) board[exceptionalCase(board)] = 2; //Exception boards.
else if (getSpace(board, corners) != -1) board[getSpace(board, corners)] = 2; //Corners
else board[getSpace(board, sides)] = 2; //Sides
}
//Prints the board to the screen.
outputBoard(board);
//Decides whether or not the game continues.
if(gameOver(board)) {
delay(2000);
for (int x = 0; x < 20; x++) digitalWrite(x, LOW);
break;
}
}
}
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