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Advent-of-Code/2020/src/main/kotlin/geometry/GridTranformations.kt

54 lines
1.4 KiB
Kotlin

package be.vandewalleh.aoc.days.geometry
import java.util.*
private fun <T> ArrayList<T>.reversed(): ArrayList<T> {
val out = ArrayList<T>(this.size)
asReversed().forEach { out.add(it) }
return out
}
fun <T> Grid<T>.flipVertically(): Grid<T> = Grid(data.reversed())
fun <T> Grid<T>.flipHorizontally(): Grid<T> {
val out = ArrayList<ArrayList<T>>(height)
for (y in 0 until height) {
out.add(data[y].reversed())
}
return Grid(out)
}
fun <T> Grid<T>.rotateRight(): Grid<T> {
val out = ArrayList<ArrayList<T>>(width)
for (x in 0 until width) {
out.add(ArrayList<T>(height))
for (y in 0 until height) {
out[x].add(data[y][x])
}
}
return Grid(out).flipHorizontally()
}
fun <T> Grid<T>.rotateLeft(): Grid<T> {
val data = flipHorizontally().data
val out = ArrayList<ArrayList<T>>(width)
for (x in 0 until width) {
out.add(ArrayList<T>(height))
for (y in 0 until height) {
out[x].add(data[y][x])
}
}
return Grid(out).flipHorizontally()
}
fun <T> Grid<T>.transformations(): Sequence<Grid<T>> = sequence {
yield(this@transformations)
yield(flipHorizontally())
yield(flipVertically())
yield(rotateLeft())
yield(rotateRight())
yield(flipHorizontally().flipVertically())
yield(flipVertically().rotateRight())
yield(flipVertically().rotateLeft())
}