62 lines
2.4 KiB
Text
62 lines
2.4 KiB
Text
|
#!/usr/bin/env kotlin
|
||
|
|
|
||
|
|
import java.io.File
|
||
|
|
import java.util.LinkedList
|
||
|
|
|
||
|
|
data class Block (
|
||
|
|
var type: Type,
|
||
|
|
var seen: Boolean = false,
|
||
|
|
var distance: Int = Int.MAX_VALUE
|
||
|
|
) {
|
||
|
|
enum class Type {
|
||
|
|
Empty,
|
||
|
|
Byte,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
val bytes = File("input.txt").readLines().subList(0, 1024).map { it.split(",").let { s -> s[0].toInt() to s[1].toInt() } }.toSet()
|
||
|
|
val grid = (0..70).map { row -> (0..70).map { col ->
|
||
|
|
Block(
|
||
|
|
type = if (bytes.contains(col to row)) Block.Type.Byte
|
||
|
|
else Block.Type.Empty,
|
||
|
|
)
|
||
|
|
}.toMutableList() }.toMutableList()
|
||
|
|
grid[0][0].seen = true
|
||
|
|
grid[0][0].distance = 0
|
||
|
|
|
||
|
|
val queue = LinkedList<Pair<Int, Int>>()
|
||
|
|
queue.addFirst(0 to 0)
|
||
|
|
|
||
|
|
while (!queue.isEmpty()) {
|
||
|
|
// Take one off the queue
|
||
|
|
val next = queue.pollLast() ?: break
|
||
|
|
|
||
|
|
// Check if we reached goal
|
||
|
|
if (next.first == 70 && next.second == 70) {
|
||
|
|
break
|
||
|
|
}
|
||
|
|
|
||
|
|
// Add neighbors
|
||
|
|
if ((0..70).contains(next.first + 1) && grid[next.first + 1][next.second].let { it.type == Block.Type.Empty && it.distance > grid[next.first][next.second].distance + 1 }) {
|
||
|
|
grid[next.first + 1][next.second].seen = true
|
||
|
|
grid[next.first + 1][next.second].distance = grid[next.first][next.second].distance + 1
|
||
|
|
queue.addFirst(next.first + 1 to next.second)
|
||
|
|
}
|
||
|
|
if ((0..70).contains(next.second + 1) && grid[next.first][next.second + 1].let { it.type == Block.Type.Empty && it.distance > grid[next.first][next.second].distance + 1 }) {
|
||
|
|
grid[next.first][next.second + 1].seen = true
|
||
|
|
grid[next.first][next.second + 1].distance = grid[next.first][next.second].distance + 1
|
||
|
|
queue.addFirst(next.first to next.second + 1)
|
||
|
|
}
|
||
|
|
if ((0..70).contains(next.first - 1) && grid[next.first - 1][next.second].let { it.type == Block.Type.Empty && it.distance > grid[next.first][next.second].distance + 1 }) {
|
||
|
|
grid[next.first - 1][next.second].seen = true
|
||
|
|
grid[next.first - 1][next.second].distance = grid[next.first][next.second].distance + 1
|
||
|
|
queue.addFirst(next.first - 1 to next.second)
|
||
|
|
}
|
||
|
|
if ((0..70).contains(next.second - 1) && grid[next.first][next.second - 1].let { it.type == Block.Type.Empty && it.distance > grid[next.first][next.second].distance + 1 }) {
|
||
|
|
grid[next.first][next.second - 1].seen = true
|
||
|
|
grid[next.first][next.second - 1].distance = grid[next.first][next.second].distance + 1
|
||
|
|
queue.addFirst(next.first to next.second - 1)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
println(grid[70][70].distance)
|