Create game_of_othello.cpp

Author: tannuchoudhary

Game Theory/game_of_othello.cpp

@@ -0,0 +1,179 @@
+#include <iostream>
+#include <vector>
+using namespace std;
+
+int** makeAMove(int** board, int x, int y, int player,int isCheck);
+
+vector<pair<int, int>*>* possibleMoves(int** board, int player) {
+	vector<pair<int, int>*>* output = new vector<pair<int, int>*>();
+	for (int i = 0; i < 4; i++) {
+		for (int j = 0; j < 4; j++) {
+			if (board[i][j] == 0) {
+				if (makeAMove(board, i, j, player, true)) {
+					pair<int, int>* p = new pair<int, int>(i, j);
+					output->push_back(p);
+				}
+			}
+		}	}
+	return output;
+}
+
+int evaluateBoard(int** board, bool& completed) {
+	if (possibleMoves(board, 1)->size() != 0 || possibleMoves(board, 2)->size() != 0) {
+		completed = false;
+		return 0;
+	}
+	// cout << "here" << endl;
+	completed = true;
+	int count[3] = {};
+	for (int i = 0; i < 4; i++) {
+		for (int j = 0; j < 4; j++) {
+			count[board[i][j]]++;
+		}
+	}
+	return count[1] - count[2];
+}
+
+int** makeAMove(int** board, int x, int y, int player,int isCheck) {
+
+	int** newBoard;
+
+	if(isCheck){
+		newBoard = board;
+	}else{
+		newBoard = new int*[4];
+		for (int i = 0; i < 4; i++) {
+			newBoard[i] = new int[4];
+			for (int j = 0; j < 4; j++) {
+				newBoard[i][j] = board[i][j];
+			}
+		}
+	}
+
+	int xDir[] = {-1,-1,0,1,1,1,0,-1};
+	int yDir[] = {0,1,1,1,0,-1,-1,-1};
+	if(x < 0 || x >= 4 || y < 0 || y >= 4 || board[x][y] != 0){
+		return NULL;
+	}
+	bool movePossible = false;
+	for(int i = 0; i < 8; i++){
+		int xStep = xDir[i];
+		int yStep = yDir[i];
+		int currentX = x + xStep;
+		int currentY = y + yStep;
+		int count = 0; 
+		while(currentX >= 0 && currentX < 4 && currentY >= 0 && currentY < 4){
+
+			if(newBoard[currentX][currentY] == 0){
+				break;
+			}else if(newBoard[currentX][currentY] != player){
+				currentX += xStep;
+				currentY += yStep;
+				count++;
+			}else{
+				if(count > 0){
+					movePossible = true;
+					if(isCheck){
+						return newBoard;
+					}
+					int convertX = currentX - xStep;
+					int convertY = currentY - yStep;
+					while(convertX != x || convertY != y){
+						newBoard[convertX][convertY] = player;
+						convertX = convertX - xStep;
+						convertY = convertY - yStep;
+					}
+					newBoard[x][y] = player;
+				}	
+				break;
+			}
+		}
+	}
+	if(movePossible){
+		return newBoard;
+	}else{
+		return NULL;
+	}
+}
+
+int kkk = 0;
+
+void printBoard(int** board) {
+	for (int i = 0 ; i < 4; i++) {
+		for(int j = 0; j < 4; j++) {
+			cout << board[i][j] << " ";
+		}
+		cout << endl;
+	}
+}
+
+int findNextStep(int** board, bool maximizerTurn, int& x, int& y) {
+	// check if done with play if yes return score of evaluate function
+	bool completed;
+	int score = evaluateBoard(board, completed);
+	printBoard(board);
+	if (completed) {
+		return score;
+	}
+
+	// find all possible moves
+	int player = maximizerTurn? 1 : 2;
+	vector<pair<int, int>*>* options = possibleMoves(board, player);
+	if (options->size() == 0) {
+		x = -1;
+		y = -1;
+		int dummyX, dummyY;
+		return findNextStep(board, !maximizerTurn, dummyX, dummyY);
+	}
+	int best;
+	if (maximizerTurn) {
+		best = INT_MIN;
+	} else {
+		best = INT_MAX;
+	}
+	// for each move 
+	for (int i = 0; i < options->size(); i++) {
+		// 	Make the move
+		int currentMoveX = options->at(i)->first;	
+		int currentMoveY = options->at(i)->second;	
+		int** newBoard = makeAMove(board, currentMoveX, currentMoveY, player, false);
+		//	Make recursive call
+		int dummyX, dummyY;
+		
+		int score = findNextStep(newBoard, !maximizerTurn, dummyX, dummyY);
+		//  update best (will be min/max depending on who's turn it is)
+		if (maximizerTurn) {
+			best = max(best, score);
+		} else {
+			best = min(best, score);
+		}
+		if (best == score) {
+			x = currentMoveX;
+			y = currentMoveY;
+		}
+		//	Undo the move. We will have to maintain a copy of the board for this.
+		for (int i = 0; i < 4; i++) {
+			delete [] newBoard[i];
+		}
+		delete [] newBoard;
+	}
+	// update x & y and return best score
+	return best;
+}
+
+int main() {
+	int **a = new int*[4];
+	for (int i = 0; i < 4; i++) {
+		a[i] = new int[4];
+		for (int j = 0; j < 4; j++) {
+			a[i][j] = 0;
+		}
+	}
+	a[1][1] = 1;
+	a[2][2] = 1;
+	a[1][2] = 2;
+	a[2][1] = 2;
+	int x, y;
+	cout << findNextStep(a, true, x, y) << endl;
+	cout << x << " " << y << endl;
+  }