Simple Sudoku solver in JavaScript for node.js or browsers.

Bored in a train, I realized that what the world needed most was another JavaScript sudoku solver...

• node.js: node parse_grid.js grids/grid1.txt in /test
• browser: just open demo.html

First, a data structure to store a Sudoku cell:

• A set of possible values.
• When this set is reduced to a single value, the cell is solved.
• Cells are immutable.

The rules of Sudoku are applied recursively to reduce the number of possible values. There is a custom iterator to scan the cells in conflict.

Finally, brute force is used to find solutions. Immutable cells make this part easier.