70 lines
1.4 KiB
Text
70 lines
1.4 KiB
Text
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#!/usr/bin/env kotlin
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import java.io.File
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enum class Direction {
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UP,
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DOWN,
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RIGHT,
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LEFT;
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fun rotate90(): Direction {
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return when (this) {
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UP -> RIGHT
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DOWN -> LEFT
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RIGHT -> DOWN
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LEFT -> UP
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}
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}
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}
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var grid = mutableListOf<MutableList<Char>>()
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var guy = Pair(0, 0);
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var direction = Direction.UP
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var i = 0
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File("./input.txt").forEachLine {
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var iter = it.chars().iterator()
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var j = 0
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grid.add(MutableList(it.length) {
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var next = iter.next().toChar()
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if (next == '^') {
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guy = Pair(i, j)
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next = '.'
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}
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j++
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next
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})
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i++
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}
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var steps = 0
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while (true) {
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val next = when (direction) {
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Direction.UP -> Pair(guy.first - 1, guy.second)
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Direction.DOWN -> Pair(guy.first + 1, guy.second)
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Direction.RIGHT -> Pair(guy.first, guy.second + 1)
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Direction.LEFT -> Pair(guy.first, guy.second - 1)
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}
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try {
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if (grid[next.first][next.second] == '#') {
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direction = direction.rotate90()
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} else if (grid[next.first][next.second] == 'X') {
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guy = next
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} else {
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grid[next.first][next.second] = 'X'
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steps++
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guy = next
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}
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} catch (_: IndexOutOfBoundsException) {
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break
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}
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}
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println(steps)
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