Solver for packing problems.
You can use this library by adding a dependency to your Cargo.toml
toml
[dependencies]
pack = "0.1.0"
The Slohouber-Graatsma puzzle asks for
packing six 1 × 2 × 2 blocks and three 1 × 1 × 1 blocks into a 3 × 3 × 3 box.
We are going to solve it with the pack library.
First we announce the use of the external crate.
rust
extern crate pack;
We need to a few things before we can start solving the puzzle. One is a
pack::puzzle::solver::Target. A target designates the volume to pack. A target
is created with a vector of pack::puzzle::piece::Positions.
```rust fn brick3x3x3() -> Target { Target::new(vec!( Position::new(0, 0, 0), Position::new(1, 0, 0), Position::new(2, 0, 0), Position::new(0, 1, 0), Position::new(1, 1, 0), Position::new(2, 1, 0), Position::new(0, 2, 0), Position::new(1, 2, 0), Position::new(2, 2, 0),
Position::new(0, 0, 1),
Position::new(1, 0, 1),
Position::new(2, 0, 1),
Position::new(0, 1, 1),
Position::new(1, 1, 1),
Position::new(2, 1, 1),
Position::new(0, 2, 1),
Position::new(1, 2, 1),
Position::new(2, 2, 1),
Position::new(0, 0, 2),
Position::new(1, 0, 2),
Position::new(2, 0, 2),
Position::new(0, 1, 2),
Position::new(1, 1, 2),
Position::new(2, 1, 2),
Position::new(0, 2, 2),
Position::new(1, 2, 2),
Position::new(2, 2, 2),
))
} ```
Because bricks are often used as targets, there is a utility
pack::util::target::brick function that does exactly that. The above code
could be replaced with brick(3, 3, 3).
One other thing we need is a pack::puzzle::pieces::Bag of
pack::puzzle::piece:Templates. A template is a shape that can be oriented in
different ways by iterating over them. A bag is a container to hold templates.
Templates are created by providing the vector of positions they occupy.
```rust fn slothoubergraatsmabag() -> Bag { Bag::new(vec!( Template::new(vec!( Position::new(0, 0, 0), Position::new(1, 0, 0), Position::new(0, 1, 0), Position::new(1, 1, 0), )), Template::new(vec!( Position::new(0, 0, 0), Position::new(1, 0, 0), Position::new(0, 1, 0), Position::new(1, 1, 0), )), Template::new(vec!( Position::new(0, 0, 0), Position::new(1, 0, 0), Position::new(0, 1, 0), Position::new(1, 1, 0), )), Template::new(vec!( Position::new(0, 0, 0), Position::new(1, 0, 0), Position::new(0, 1, 0), Position::new(1, 1, 0), )), Template::new(vec!( Position::new(0, 0, 0), Position::new(1, 0, 0), Position::new(0, 1, 0), Position::new(1, 1, 0), )), Template::new(vec!( Position::new(0, 0, 0), Position::new(1, 0, 0), Position::new(0, 1, 0), Position::new(1, 1, 0), )),
Template::new(vec!(
Position::new(0, 0, 0),
)),
Template::new(vec!(
Position::new(0, 0, 0),
)),
Template::new(vec!(
Position::new(0, 0, 0),
)),
))
} ```
Finally we need to tell the solve function what to do when they find a
solution. This can be done by passing a clojure. For this example we will just
print the solution.
Our main function could look like the following code.
```rust fn main(){ let target = brick(3, 3, 3); let bag = slothoubergraatsmabag(); let partial_solution = Solution::empty();
solve(target, bag, partial_solution, &mut |solution|{
println!("{}", solution)
});
} ```
Running it will eventually print a solution to the Slothouber-Graatsma puzzle. The full source for this example can be found in examples/slothouber-graatsma.rs. For a more extensive documentation see the wiki.