问题:有三只大虎(A,B,C)和三只小虎(a,b,c),正好母子三对,要过一条河,岸边有一条船,一次最多只能载两只虎,今知三只大虎和小虎a能划船。限制条件是,只有自已的母虎在身边,小虎才能与其他母虎同船、同岸或岸边遭遇,不然会被吃掉。请问怎样往返渡船,才能使六只虎平安过河。 Question: There are three big tigers (A, B, C) and three tigers (a, b, c), just three pairs of mothers and sons. To cross a river, there is a boat on the shore. At most one can hold only two tigers. Today we know that three big tigers and tigers can row a boat. The restriction is that only the own female tiger is around, and the tiger can encounter the other female tiger on the same ship, on the shore or on the shore, or it will be eaten. How can the ferry cross the river safely?