Java Space Invaders游戏快速触发作弊触发游戏获胜太早

Question

So I am new the very new programmer modifying/adding things to a already made space invaders game to get more familiar with how games are programmed. I am trying to add cheats to the game and the rapid fire cheat is giving me some trouble. When you choose rapid fire and go through the level, the game can sometimes trigger the notifyWin early with some aliens still left. This is because sometimes 2 shots hit the same enemy at the exact same time making the computer think that 2 different enemies are being killed, thus leaving a few aliens sometimes left over while the "You have won!" screen pops up. The win is triggered when the alien count reaches 0 shooting the same enemy twice reduces the alien count by 2 instead of 1. I can't for the life of me seem to figure this out.

// reduce the alient count, if there are none left, the player has won
    alienCount--;

if (alienCount == 0)
    {
        notifyWin ();
    }

Here is the code where the shot collides with the enemy

/**
     * Notification that this shot has collided with another
     * entity
     * 
     * @parma other The other entity with which we've collided
     */
    public void collidedWith(Entity other) {
            // prevents double kills, if we've already hit something,
            // don't collide
            if (used) {
                    return;
            }

            // if we've hit an alien, kill it!
            if (other instanceof AlienEntity) {
                    // remove the affected entities
                    game.removeEntity(this);
                    game.removeEntity(other);

                    // notify the game that the alien has been killed
                    game.notifyAlienKilled();
                    used = true;
            }
    }

Answer 1

One possible solution is to add the enemies as objects to a list. When they have been shot, remove them from the list, checking that they are still there before hand. Do a notifyWin when the list is empty. This way, if the logic doing the collision detection on the enemies generates too many hits, it will still work correctly.

The chances are good that this list exists already in order to render the enemies on the screen.

EDIT : now that I see the method, you could probably just do the following at the top of collidedWith:

if (used || !game.containsEntity(other)) {
    return;
}

Where the method containsEntity checks for the existence of the entity in the internal list or structures that hold the game actors (entities).