jbosboom/pathpuzzle-solver

Solves path puzzles

pathpuzzle-solver

This is a solver for path puzzles. For copyright reasons, only the font from our path puzzles hardness paper is included in this repository.

Solver input format

You probably don't want to enter puzzles directly in this format. Instead, use the Python preprocessing script described below.

The input is a series of lines that start with a single character followed by one or integers, space separated. The first line should be of the form s a b c where a is the number of cells in the puzzle, b is the number of counters (clues, plus one dummy counter), and c is the number of terminals (doors). Then, in any order:

• a n r c n1 n2 n3 n4 c1 c2 c3 c4 specifies a cell. n is the index of the cell (starting at 0), r and c are the row and column respectively, n1 through n4 are the indices of the cell's neighbors (use -1 if there are fewer than four neighbors) and c1 through c4 are the counters covering the cell (use the dummy counter if there are fewer than four).
• c n v specifies a counter, which usually corresponds to a clue. n is the index of the counter and v is the counter's initial value. There should be one dummy counter, conventionally numbered 0, whose initial value is -1; this counter is used so that every cell is covered by four counters even if it isn't covered by four clues.
• t i specifies that the cell with index i is a terminal (door).

More convenient input formats

preprocess.py takes as input a tab-separated file where x denotes a normal cell, T denotes a terminal, and numbers denote clues with that value. This makes it easy to draw a puzzle in a spreadsheet program and export as TSV.

For rectangular puzzles (like the font), there is a simpler input format consisting of just the row and column clues (- for a missing clue) and terminals as row-column pairs. See the font for examples. Pass the --font argument to preprocess.py to use this format.