minimax problems

Moagly · 2002-11-14T03:25:03

Could someone please help me, i am trying to implement the minimax algorithm in c++ in a simple tic tac toe game. however my minimax function just returns the first move it can find rather than the best move here is my minimax class: int AIMinimaxAgent::findBestMove(bool nodeType, Board b, int depth) { if((depth == 0)) return b.evaluateBoard(); Board c; // temp board int best; // the best so far for this level int value; // the value for each node // which node are we looking at? switch(nodeType) { // min node, i.e. human move case MINNODE : { best = 99; // for each square for(int i=0;i<9;i++) { // make a copy of the board c.copy(b); // if this move is legal if(c.isLegal(i)) { //make the move c.makeMove(X, i); value = findBestMove(!nodeType, c, depth-1); // if this move is less than the best at this level if(value < best) best = value; // update the best // unmake the move so the next move can be tested c.setSquares(EMPTY, i); } } // return the best score that was found return best; } break; // max node, i.e computer move case MAXNODE : { best = -99; // for each square for(int i=0;i<9;i++) { // make a copy of the board c.copy(b); // if this move is legal if(c.isLegal(i)) { // make the move c.makeMove(O, i); // find the best move from this position value = findBestMove(!nodeType, c, depth-1); // if this move is better than the current best for this level if(value > best) best = value; // update the best score // unmake the move so we can test the next move c.setSquares(EMPTY, i); } } // return the best score found for this level of recursion return best; } break; } return 0; } int AIMinimaxAgent::getMove(Board b) { int best; int value; int theMove; for(int i=0;i<9;i++) { if(b.isLegal(i)) { b.setSquares(EMPTY, i); value = findBestMove(MINNODE, b, 6); if(value > best) { best = value; theMove = i; } } } return theMove; } and here is my evaluation function : int Board::evaluateBoard() { if(isWin()) { switch(winner) { case HUMAN : return -1; case COMPUTER : return 1; } } if(numPieces = 9) return 0; } if anyone has any ideas what is wrong please help me!

Artificial Intelligence Programming

Started by Moagly November 08, 2002 09:49 AM

10 comments, last by Moagly 22 years ago

Moagly

Author

160

November 13, 2002 07:47 AM

Sorry forgot to type password!

Moagly

Author

160

November 14, 2002 03:25 AM

Ha! Finally got it to work, was absolutly nothing wrong with minimax! it was my isWin that was the problem! wasn''t checking for every win!

thanx for all your help anyway!

minimax problems

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

minimax problems

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Reticulating splines