zoj 1004 的题目，这是一个经典的水壶倒水问题，题目中没有要求最少的次数倒满水，所以还可以不用bfs，本题用了bfs-zoj 1004 topics, this is a classic problem of water pouring money down the drain, the title does not require a minimum number of filling water, so it can be bfs, the title used bfs