Came across the following flash logical problem. For crossing river/bridge type of problems, this one is one of the hardest.
If you cannot read Chinese, here are the rules and instructions:
There are a family of six: Dad, Mom, two sons, and two daughters. There is a policeman and a thief.
1. The objective of the game is to get everyone across the river in a boat.
2. The boat can take a maximum of two persons.
3. Only the Dad, the Mom, or the Policeman can operate the boat.
4. The family members cannot be with the thief without the presence of the policeman.
5. The daughters cannot be with the Dad without the presence of the Mom.
6. The sons cannot be with the Mom without the presence of the Dad.
To play the game:
Click the big blue circle to start. Click on the persons to pick them to get on the boat. Click the red switch to send the boat to the opposite side.