Backtracking Algorithms

A backtracking algorithm solves a Sudoku by trying to place a digit into a cell, then working out the consequences and placing other digits until the program either hits a dead end, or finds a solution. If a dead end is reached, the algorithm then removes the placed digits and tries the alternatives. This process continues until all alternatives have been tried.

Another name for backtracking is depth-first search.

Popular backtracking algorithms for Sudoku are Dancing Links, also known by its acronym DLX, and Ariadne's Thread.

The topic in this article is a still a subject of debate. Parts of the text may not express everybody's opinion. Use the associated Talk page if you do not agree with the opinion of the writer, rather than continuously editing the main article.