AoC24-2ab

import Foundation

struct Report {
  var levels: [Int]

  init(_ levels: [Int]) {
    self.levels = levels
  }

  func isSteady() -> Bool {
    var steady: Bool
    if levels == levels.sorted() || levels.reversed() == levels.sorted() {
      steady = true
    } else {
      steady = false
    }

    return steady
  }

  func isGradual() -> Bool {
    var gradual = true
    for i in 0..<(levels.count-1) {
      let check = abs(levels[i] - levels[i+1])
      if (check < 1 || check > 3) {
        gradual = false
        break
      }
    }

    return gradual
  }
}

// Reads in and stores the input
func getReports(from file: String) -> [Report] {
  var input = (try? String(contentsOf: URL(fileURLWithPath: file)))!
  if input[input.index(before: input.endIndex)] != "\n" {
    input.append("\n")
  }

  var reports = [Report]()

  var tempList = [Int](), tempEntry = ""
  for c: Character in input {
    if c >= "0" && c <= "9" {
      tempEntry.append(c)
    } else if c == " " && tempEntry != "" {
      tempList.append(Int(tempEntry)!)
      tempEntry = ""
    } else if c == "\n" {
      tempList.append(Int(tempEntry)!)
      tempEntry = ""
      reports.append(Report(tempList))
      tempList.removeAll()
    }
  }

  return reports
}

// Part 1 magic
func getTotal1(of reports: [Report]) -> Int {
  var total = 0
  for r in reports {
    total += (r.isSteady() && r.isGradual() ? 1 : 0)
  }

  return total
}

// Part 2 magic
func getTotal2(of reports: [Report]) -> Int {
  var total = 0
  for r in reports {
    var steady = r.isSteady(), gradual = r.isGradual()
    if !steady || !gradual {
      for i in 0..<r.levels.count {
        var temp = r
        temp.levels.remove(at: i)
        if temp.isSteady() && temp.isGradual() {
          steady = true
          gradual = true
        }
      }
    }
    total += (steady && gradual ? 1 : 0)
  }

  return total
}

// int main()
let reports = getReports(from: "input.txt")

let total1 = getTotal1(of: reports)
print("Part 1 answer: \(total1)")
let total2 = getTotal2(of: reports)
print("Part 2 answer: \(total2)")