Suguru Solver

by trosh

Coded in ugly C© ♥ ♥

building

running make inside the main directory should build a suguru executable.

usage

./suguru FILE.sgr

for example, ./suguru grids/s_v1_b16_3.sgr

notes

the process is relatively simple: the program loads the grid from a .sgr file, then iterates through {values, regions} passes.

• values passes go through each cell in row major order, affects neighbour cells' possibilities, then do a second pass to find cells with only one possibility left.
• regions passes go through each regions to remove possibilities according to completed cells within the region, search for possibilities that appear in only one cell, then search for single cells outside of region that touch every cell within region for each possibility.

The storage is relatively compressed, since the same full grid is used to store possibilities and final values: in each cell,

• if a value is positive, it is worth the final value
• otherwise its 5 lowest bits describe possibilities.

todo

• encapsulate iterator
• add user options