Minimax Alpha-Beta Pruning

MinimaxAlphaBeta.java

    public static void main(String[] args) {
		Tree tree = initialise();
		System.out.println(minimax(tree.getRoot(), 2,
				Integer.MIN_VALUE, Integer.MAX_VALUE, true));
	}
	
	private static int minimax(Node node, int depth, int alpha, int beta, boolean isMax) {
		if(depth==0 || node.getChildren()==null || node.getChildren().isEmpty()) {
			return getStateScore(); //evaluation function
		}
		if(isMax) {
			for(Node child:node.getChildren()) {
				alpha = Math.max(alpha, minimax(child, depth-1, alpha, beta, false));
				if(alpha>=beta) {
				   break; //pruning
				}
			}
			return alpha;
		}else {
			for(Node child:node.getChildren()) {
				beta = Math.min(beta, minimax(child, depth-1, alpha, beta, true));
				if(alpha>=beta) {
				   break; //pruning
				}
			}
			return beta;
		}
	}