83 lines
2.0 KiB
Swift
83 lines
2.0 KiB
Swift
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//
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// File.swift
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//
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//
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// Created by Max Nuding on 05.12.21.
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//
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import Foundation
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import Runner
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import Collections
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struct Coord {
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let row: Int
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let col: Int
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func getLeft() -> Coord? {
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guard col > 0 else {
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return nil
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}
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return Coord(row: row, col: col - 1)
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}
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func getRight() -> Coord { Coord(row: row, col: col + 1) }
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func getAbove() -> Coord? {
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guard row > 0 else {
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return nil
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}
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return Coord(row: row - 1, col: col)
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}
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func getBelow() -> Coord { Coord(row: row + 1, col: col) }
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}
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struct Field {
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let numbers: [[Int]]
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let numCols: Int
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let numRows: Int
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init(numbers: [[Int]]) {
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self.numbers = numbers
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numCols = numbers.first!.count
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numRows = numbers.count
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}
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func getNeighborsCoordsFor(coord: Coord) -> [Coord] {
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return [coord.getAbove(), coord.getRight(), coord.getBelow(), coord.getLeft()]
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.compactMap { $0 }
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.filter { $0.row < numRows && $0.col < numCols }
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}
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func lowPointValueAt(coord: Coord) -> Int? {
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let value = numbers[coord.row][coord.col]
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return getNeighborsCoordsFor(coord: coord)
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.map { numbers[$0.row][$0.col] }
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.allSatisfy { $0 > value }
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? value
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: nil
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}
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}
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struct Day09: Runnable {
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let inputPath: String
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func run() {
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let input = try! String(contentsOfFile: inputPath)
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let entries = input
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.trimmingCharacters(in: .newlines)
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.components(separatedBy: .newlines)
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.map { line in line.map { $0.wholeNumberValue! } }
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let field = Field(numbers: entries)
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var sum = 0
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for row in 0..<field.numRows {
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for col in 0..<field.numCols {
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if let lpv = field.lowPointValueAt(coord: Coord(row: row, col: col)) {
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sum += lpv + 1
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}
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}
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}
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print(sum)
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}
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}
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