如何设计依赖关系列表并存储它

I am working on a game which as a series of quests. There are many quests available to the user at any time, however certain quests depend on others being completed first before they are available. You can look to WoW for possibly the best implementation of this. As you complete various quests, then game state is updated to reflect new options available to the user.I am working on a game which as a series of que