River Crossing River Wolf Goat Cabbage Easy — Set 90

Easy River Crossing Puzzle #90

Title

Easy River Crossing Puzzle #90

Scenario

Wolf, Goat & Cabbage

Narrative

A farmer must cross a river with a wolf, a goat, and a cabbage. The boat can carry only the farmer and one other passenger.

Entities

• {"id":"wolf","name":"Wolf","icon":"\ud83d\udc3a"}
• {"id":"goat","name":"Goat","icon":"\ud83d\udc10"}
• {"id":"cabbage","name":"Cabbage","icon":"\ud83e\udd6c"}

BoatCapacity

1

Constraints

• The wolf cannot be left alone with the goat.
• The goat cannot be left alone with the cabbage.

Question

Describe a valid sequence of crossings that gets everyone to the other side without violating any constraint. What is the minimum number of trips required?

Solution

• {"trip":1,"direction":"\u2192","carrying":["Goat"],"leftBank":["Wolf","Cabbage"],"rightBank":["Goat"],"note":"Take the goat first."}
• {"trip":2,"direction":"\u2190","carrying":[],"leftBank":["Wolf","Cabbage","Farmer"],"rightBank":["Goat"],"note":"Return empty."}
• {"trip":3,"direction":"\u2192","carrying":["Wolf"],"leftBank":["Cabbage"],"rightBank":["Goat","Wolf"],"note":"Take the wolf."}
• {"trip":4,"direction":"\u2190","carrying":["Goat"],"leftBank":["Cabbage","Goat"],"rightBank":["Wolf"],"note":"Bring goat back."}
• {"trip":5,"direction":"\u2192","carrying":["Cabbage"],"leftBank":["Goat"],"rightBank":["Wolf","Cabbage"],"note":"Take the cabbage."}
• {"trip":6,"direction":"\u2190","carrying":[],"leftBank":["Goat","Farmer"],"rightBank":["Wolf","Cabbage"],"note":"Return empty."}
• {"trip":7,"direction":"\u2192","carrying":["Goat"],"leftBank":[],"rightBank":["Wolf","Cabbage","Goat"],"note":"Take goat. Done!"}

MinimumTrips

7

Hint

The first 3 move(s) of the solution are shown below to help you start.

PartialSolutionHint

• {"trip":1,"direction":"\u2192","carrying":["Goat"],"leftBank":["Wolf","Cabbage"],"rightBank":["Goat"],"note":"Take the goat first."}
• {"trip":2,"direction":"\u2190","carrying":[],"leftBank":["Wolf","Cabbage","Farmer"],"rightBank":["Goat"],"note":"Return empty."}
• {"trip":3,"direction":"\u2192","carrying":["Wolf"],"leftBank":["Cabbage"],"rightBank":["Goat","Wolf"],"note":"Take the wolf."}