package aoc.day11

import aoc._
import scala.annotation.tailrec

val board = lines.toSeq

// part 1

val countByRow = board.map(_.count(_ == '#')).toList
val countByCol = (0 until board(0).length()).map(col => board.count(row => row(col) == '#')).toList

@tailrec def totalDist(expandBy: Int)(count: Long, leftDist: Long, accum: Long)(counts: List[Int]): Long =
  counts match
    case Nil       => accum
    case 0 :: next => totalDist(expandBy)(count, leftDist + expandBy * count /* expanded case */, accum)(next)
    case cur :: next =>
      totalDist(expandBy)(count + cur, leftDist + count + cur, accum + cur * leftDist)(next)

def totalDist(expandBy: Int)(counts: List[Int]): Long = totalDist(expandBy)(0, 0, 0)(counts)

def part1 =
  inline def count(r: List[Int]): Long = totalDist(2)(r)
  val res = count(countByRow) + count(countByCol)
  println(res)

def part2 =
  inline def count(r: List[Int]): Long = totalDist(1_000_000)(r)
  val res = count(countByRow) + count(countByCol)
  println(res)

@main def Day11(part: Int) = part match
  case 1 => part1
  case 2 => part2