Prancing Pony

Even from the outside the inn looked a pleasant home to familiar eyes. A sign above the door pictured a fat white pony rearing on its hind legs. Over the door was painted the letters: THE PRANCING PONY by BARLIMAN BUTTERBALL.

Prancing Pony is a simple implementation of the Knight's Tour using the backtracking strategy for variable board sizes and variable starting positions. It is guaranteed to find a solution and will know immediately if the given parameters have no possible Tour.

Because this is a brute force and naive O(n!) solution, it should NOT be expected to find a result in the given parameters in most configurations, however it should behave well for small boards (less than 40 squares) or traditional boards with 8x8 size starting at position (0,0).

Usage

let tour_input = prancing_pony::TourInput {
    size_x: 8,
    size_y: 8,
    starting_position: (0,0)
};

let result = prancing_pony::find_solution(tour_input);

match result {
    prancing_pony::TourResult::Solution(t) => {
        println!("Solution found in {} nanoseconds after {} backtracks", t.calculation_time, t.times_backtracked);
        for (index, position) in t.position_history.iter().enumerate() {
            println!("{} - ({} {})", index, position.0, position.1);
        }
    },
    prancing_pony::TourResult::NoSolution => {  println!("No Solution"); },
    prancing_pony::TourResult::InvalidParameters => { println!("Invalid Parameters"); }
}