Advent of Kotlin 2018 Week 1

Solution for Week 1 of Advent of Kotlin.

It is based on the A* algorithm, which finds one of the optimal paths with good performance by using an additional heuristic. The A* algorithm is otherwise similar to the widely-known Dijkstra algorithm.

Two of the original tests have been adjusted to a different, but still perfect path in terms of cost (see comments in the tests).

Project Structure

This is a normal Gradle project. The code can be found in the src/main folder; The tests are in src/test. The project can be built with:

./gradlew build

This compiles the code and runs all tests and static code checks.

Benchmark

These are the results of an JMH benchmark (navigate on forest test) on a Linux 4.19.2 device with an
Intel® Core™ i7-7700T CPU @ 2.90GHz × 8:

Benchmark	Mode	Cnt	Score	Error	Units
PathFinderBenchmark.addPath	thrpt	25	1373,390	± 5,883	ops/s

To reproduce, run:

./gradlew jmh