/**
 * Keeps track of what numbers have been called
 * in a game of bingo.
 * @author Jeff Raab
 */
public class BingoNumbers {
    
    /** What numbers have been called. */
    protected boolean[] called;
    
    /** Constructs a new bingo numbers object. */
    public BingoNumbers() {
        called = new boolean[76];
    }
    
    /** 
     * Stores the fact that the given number has been called. 
     * @param num number to call
     */
    public void call(int num) {
        if ((num < 1) || (num > 75)) {
            throw new RuntimeException("Number out of range");
        }
        
        if (isCalled(num)) {
            throw new RuntimeException("Number already called");
        }
        
        called[num] = true;
    }
    
    /**
     * Returns whether or not the given number is called.
     * @param num number to check
     */
    public boolean isCalled(int num) {
        if ((num < 1) || (num > 75)) {
            throw new RuntimeException("Number out of range");
        }
        
        return called[num];
    }
    
    /** Sets that no numbers have been called. */
    public void newGame() {
        for (int i = 0; i < called.length; i++) {
            called[i] = false;
        }
    }
}