{"id":673,"date":"2026-01-21T20:03:40","date_gmt":"2026-01-21T20:03:40","guid":{"rendered":"https:\/\/camilo.matajira.com\/?p=673"},"modified":"2026-01-27T19:16:02","modified_gmt":"2026-01-27T19:16:02","slug":"my-failed-sudoku-solver-in-rust","status":"publish","type":"post","link":"https:\/\/camilo.matajira.com\/?p=673","title":{"rendered":"My failed sudoku solver in Rust"},"content":{"rendered":"\n

For this project, I decided to revisit my classic sudoku solver: A project I like to implement whenever I\u2019m learning a new programming language. The sudoku solver was my first personal project which I originally wrote in Java in 2008. Since then, I\u2019ve recreated it in Python (https:\/\/camilo.matajira.com\/?p=220<\/a>) and JavaScript as well.<\/p>\n\n\n\n

This time, I was eager to try implementing it in Rust. However, the experience was somewhat lukewarm. While I learned a lot about the language, I wasn\u2019t able to compile the code including the last function (the solver that joined all together.) The code compiled all the way, until the very last step.<\/p>\n\n\n\n

The technical issue:<\/strong>
I wanted to create a linked list of Cell<\/code> objects, where each Cell<\/code> kept a reference to the next Cell<\/code>, and the solver has a Cell<\/code> as parameter, and a reference to the head of the linked list. To trigger the solver, I needed to provide a mutable reference to the head (the initial Cell<\/code> of the puzzle) as well as another (possibly mutable) reference to the head, so that each Cell<\/code> could compute the “state” of the game (see the snippet below).
The Rust compiler didn\u2019t allow this, and despite all kinds of acrobatics and efforts, I couldn\u2019t get the code to compile.<\/p>\n\n\n\n

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