Full screen... (click)The Japanese employers use this test to hire employees in the IT sector. You should get all the people to the other side of the river. Either learn Chinese (in which the game above is written) or click the blue disk for the game to start. Clicking a person moves him or her to or from the boat. Right-click the Flash and choose "rewind" to start from the scratch.
- The boat only operates with 1 or 2 people aboard; press a stick with the red button(s) to move
- The mother, the father, or cop are needed for the boat to move
- The prisoner kills any member of the family if the cop is not there as well
- The mother kills a son if the father is not around
- The father kills a daughter if the mother is not around
As Peter points out, there are only two solutions that are charge (=sex, except for the cop and prisoner who are sex-neutral) conjugate to each other. Each solution by itself is CPT-symmetric. ;-) When you run it backwards in time (time reversal), replace the two sides of the river (parity), and exchange the sexes (charge conjugation), you get the same thing.
A simpler version with cabbage, goat, and wolf has been known for years.