package ru.timakden.aoc.year2015

import ru.timakden.aoc.util.measure
import ru.timakden.aoc.util.readInput

/**
 * [Day 3: Perfectly Spherical Houses in a Vacuum](https://adventofcode.com/2015/day/3).
 */
object Day03 {
    @JvmStatic
    fun main(args: Array<String>) {
        measure {
            val input = readInput("year2015/Day03").single()
            println("Part One: ${part1(input)}")
            println("Part Two: ${part2(input)}")
        }
    }

    fun part1(input: String): Int {
        var x = 0
        var y = 0

        return input.map {
            when (it) {
                '^' -> y++
                'v' -> y--
                '<' -> x--
                '>' -> x++
            }

            x to y
        }.plus(0 to 0).distinct().size
    }

    fun part2(input: String): Int {
        var santaX = 0
        var santaY = 0
        var robotX = 0
        var robotY = 0
        var counter = 0

        return input.map {
            val isCounterEven = counter % 2 == 0

            when (it) {
                '^' -> if (isCounterEven) santaY++ else robotY++
                'v' -> if (isCounterEven) santaY-- else robotY--
                '<' -> if (isCounterEven) santaX-- else robotX--
                '>' -> if (isCounterEven) santaX++ else robotX++
            }

            counter++

            if (isCounterEven) santaX to santaY else robotX to robotY
        }.plus(0 to 0).distinct().size
    }
}
