Introduction - If you have any usage issues, please Google them yourself
Problem description farmer across the river is a farmer with a wolf, a sheep and a cabbage, in the south bank of the river, and he brought these things to north. However, only a small boat in front of him, but he could only bring one thing each river, as the relationship between food chain, he can not leave the wolf and the sheep at the same time, nor can the sheep and cabbage leaves at the same time, but it can be the wolf and Chinese cabbage leaves at the same time. Write a code to describe the farmer across the river used method.