Solving the River Crossing Puzzle with Go
Programming Snapshot – Go Game States

© Lead Image by am not, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=18656684
How does a ferryman transport a wolf, a goat, and a cabbage across a river in a boat that can only carry the ferryman plus one item at a time, without the wolf eating the goat or the goat eating the cabbage while left together back on shore? Mike programs the solution in Go.
Whether it is a wolf, a goat, and a cabbage, or one of the many variations on this scenario, keeping the participants safe during passage is part of the classic river crossing logic puzzle [1]. Humans find a solution to these brainteasers by trial and error. Computers, on the other hand, determine the solution by exploring trees of interlinked state sequences, eventually arriving at the desired final state by following one of many different available paths [2].
Before crossing the river, the ferryman, the wolf, the goat, and the cabbage are initially on the west bank. The ferryman can only take one of the three candidates into the boat and cross over to the east bank. During the crossing, he has to take care not to leave the wolf and goat alone on the bank, because the wolf would eat the goat. The same applies to the goat and the cabbage, as goats like to eat cabbage.
The riddle seems unsolvable at first. For example, once the ferryman has crossed the river with the goat and returns on an empty run, the only choice he has is between the wolf and the cabbage as the next candidate. However, neither will get along with the goat on the other bank. The trick is that the ferryman can also carry passengers on the return journey, thus ensuring that he never leaves a dangerous combination (goat/cabbage or wolf/goat) unattended.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

News
-
OpenMandriva Lx 6.0 Available for Installation
The latest release of OpenMandriva has arrived with a new kernel, an updated Plasma desktop, and a server edition.
-
TrueNAS 25.04 Arrives with Thousands of Changes
One of the most popular Linux-based NAS solutions has rolled out the latest edition, based on Ubuntu 25.04.
-
Fedora 42 Available with Two New Spins
The latest release from the Fedora Project includes the usual updates, a new kernel, an official KDE Plasma spin, and a new System76 spin.
-
So Long, ArcoLinux
The ArcoLinux distribution is the latest Linux distribution to shut down.
-
What Open Source Pros Look for in a Job Role
Learn what professionals in technical and non-technical roles say is most important when seeking a new position.
-
Asahi Linux Runs into Issues with M4 Support
Due to Apple Silicon changes, the Asahi Linux project is at odds with adding support for the M4 chips.
-
Plasma 6.3.4 Now Available
Although not a major release, Plasma 6.3.4 does fix some bugs and offer a subtle change for the Plasma sidebar.
-
Linux Kernel 6.15 First Release Candidate Now Available
Linux Torvalds has announced that the release candidate for the final release of the Linux 6.15 series is now available.
-
Akamai Will Host kernel.org
The organization dedicated to cloud-based solutions has agreed to host kernel.org to deliver long-term stability for the development team.
-
Linux Kernel 6.14 Released
The latest Linux kernel has arrived with extra Rust support and more.