dkandalov/kotlin-99

Ninety-Nine Problems in Kotlin

kotlin-99's Issues

Tree and Node design

1. Is it a good decision to model “no node" as End object? Or should it be null or may be a class?
2. What is the best way to model Nodes with XY position? I decided to wrap node value into object which has coordinates, unlike for example this solution http://aperiodic.net/phil/scala/s-99/p64.scala where they define PositionedNode class.

P86 for directed graphs

Dancing link header label cast to Int

org.kotlin99.misc.SudokuDancingLinks.ExactCoverMatrix.Companion#toSudokuBoard
does it.header.toString().toInt(). This should be refactored, e.g. to use Int as Node label.

Create git branch with tests only

Improve intro text for Graphs

The text was mostly copied from 99 scala problems and overall is too verbose.
Probably it should also explain existing Kotlin API for graphs.

Graph design

• overall Graph class seems a bit more complicated than you'd expect
• Node has U type parameter only to pass it into Edge
• there are too many methods in Graph companion object, ideally directed/undirected, labelled/unlabelled, terms/adjacency list should be "orthogonal"
• comparator in P84

  kotlin-99/src/org/kotlin99/graphs/P84.kt

  Line 18 in 8230bfa

  val comparator = Comparator<Edge<T, U>> { e1, e2 ->

Rename ContainsAll matchers

Because there are really "equal to ignoring order" matchers.