quickbacktrack

Library for back tracking with customizable search for moves

Back tracking is a general algorithm for finding solutions to constraint satisfaction problems.

With other words, it solves puzzles like Sudoku or Knapsack!

Blog posts:

• 2020-10-16 Quickbacktrack 0.7 Released
• 2017-08-09 Quickbacktrack 0.3 Released

Features

• Customizable search for moves
• Debug settings for watching the solving in real time
• Solve simple steps to reduce debug output
• Trait Puzzle for solving generic constraint satisfaction problems
• Can start with non-empty puzzle
• Can get difference from initial puzzle state

Sudoku

 ___ ___ ___
|43 | 8 |7  |
|17 | 34|8  |
|85 | 6 |3  |
 ---+---+---
|964|153|287|
|285|497|136|
|713|826|945|
 ---+---+---
|521|349|678|
|347|61 |5  |
|698| 7 |413|
 ---+---+---
Guess [8, 1], 9 depth ch: 6 prev: 38 it: 7

To run, open up Terminal and type:

cargo run --example sudoku

Knapsack

Item { desc: "chocolate", weight: 0.2, value: 40 }
Item { desc: "book", weight: 0.5, value: 300 }
Item { desc: "hat", weight: 0.1, value: 1000 }
total weight: 0.7999999999999999
total value: 1340

To run, open up Terminal and type:

cargo run --example knapsack

8 Queens

 _ _ _ _ _ _ _ _
|_|_|_|_|_|_|_|x|
|_|_|_|x|_|_|_|_|
|x|_|_|_|_|_|_|_|
|_|_|x|_|_|_|_|_|
|_|_|_|_|_|_|_|_|
|_|_|_|_|_|_|_|_|
|_|_|_|_|_|_|_|_|
|_|_|_|_|_|_|_|_|

Guess 6, 7 depth ch: 5 prev: 5 it: 72

To run, open up Terminal and type:

cargo run --example eight_queens