Advent of Code Day 3

AoC_2019_Day3.swift

#!/usr/bin/env xcrun swift

import Foundation

let input = """
R999,U626,R854,D200,R696,D464,R54,D246,L359,U57,R994,D813,L889,U238,L165,U970,L773,D904,L693,U512,R126,D421,R732,D441,R453,D349,R874,D931,R103,D794,R934,U326,L433,D593,L984,U376,R947,U479,R533,U418,R117,D395,L553,D647,R931,D665,L176,U591,L346,D199,L855,D324,L474,U251,R492,D567,L97,D936,L683,U192,R198,U706,L339,U66,R726,D102,R274,U351,R653,D602,L695,U921,R890,D654,R981,U351,R15,U672,R856,D319,R102,D234,R248,U169,L863,U375,L412,U75,L511,U298,L303,U448,R445,U638,L351,D312,R768,D303,L999,D409,L746,U266,L16,U415,L951,D763,L976,U342,L505,U770,L228,D396,L992,U3,R243,D794,L496,U611,R587,U772,L306,D119,L470,D490,L336,U518,L734,D654,L150,U581,L874,U691,L243,U94,L9,D582,L402,U563,R468,U96,L311,D10,R232,U762,R630,D1,L674,U685,R240,D907,R394,U703,L64,U397,L810,D272,L996,D954,R797,U789,R790,D526,R103,D367,R143,D41,L539,D735,R51,D172,L33,U241,R814,D981,R748,D699,L716,U647,L381,D351,L381,D121,L52,U601,R515,U713,L404,U45,R362,U670,L235,U102,R373,U966,L362,U218,R280,U951,R371,U378,L10,U670,R958,D423,L740,U888,R235,U899,L387,U167,R392,D19,L330,D916,R766,D471,L708,D83,R749,D696,L50,D159,R828,U479,L980,D613,L182,D875,L307,U472,L317,U999,R435,D364,R737,U550,L233,U190,L501,U610,R433,U470,L801,U52,L393,D596,L378,U220,L967,D807,R357,D179,L731,D54,L804,D865,L994,D151,L181,U239,R794,D378,L487,U408,R817,U809,R678,D599,L564,U480,R525,D189,L641,D771,L514,U72,L248,D334,L859,D318,R590,D571,R453,U732,R911,U632,R992,D80,R490,D234,L710,U816,L585,U180,L399,D238,L103,U605,R993,D539,R330
L996,U383,L962,U100,L836,D913,R621,U739,R976,D397,L262,D151,L12,U341,R970,U123,L713,U730,L52,D223,L190,D81,R484,D777,R374,U755,R640,D522,R603,D815,R647,U279,R810,U942,R314,D19,L938,U335,R890,U578,R273,U338,R186,D271,L230,U90,R512,U672,R666,D328,L970,U17,R368,D302,L678,D508,L481,U12,L783,D409,L315,D579,L517,D729,R961,D602,R253,D746,R418,D972,R195,D270,L46,D128,L124,U875,R632,D788,L576,U695,R159,U704,R599,D597,R28,D703,L18,D879,L417,U633,L56,U302,R289,U916,R820,D55,R213,U712,R250,D265,L935,D171,L680,U738,L361,D939,R547,D606,L255,U880,R968,U255,R902,D624,L251,U452,L412,D60,L996,D140,L971,U196,R796,D761,L54,U54,L98,D758,L521,U578,L861,U365,L901,D495,L234,D124,L121,D329,L38,U481,L491,D938,L840,D311,L993,D954,R654,U925,L528,D891,L994,D681,L879,D476,L933,U515,L292,U626,R348,D963,L145,U230,L114,D11,R651,D929,R318,D672,R125,D827,L590,U338,L755,D925,L577,D52,R131,D465,R657,D288,R22,D363,R162,D545,L904,D457,R987,D389,L566,D931,L773,D53,R162,U271,L475,U666,L594,U733,R279,D847,R359,U320,R450,D704,L698,D173,R35,D267,L165,D66,L301,U879,R862,U991,R613,D489,L326,D393,R915,U718,R667,U998,R554,U199,R300,U693,R753,U938,R444,U12,L844,D912,R297,D668,R366,U710,L821,U384,R609,D493,R233,U898,R407,U683,R122,U790,L1,U834,L76,U572,R220,U752,L728,D85,L306,D805,R282,U507,R414,D687,L577,U174,L211,U308,L15,U483,R741,D828,L588,D192,L409,D605,L931,U260,L239,D424,L846,U429,L632,U122,L266,D544,R248,U188,R465,U721,R621,U3,L884,U361,L322,U504,R999,U381,R327,U555,L467,D849,R748,U175,R356
"""

let wires = try! input.split { $0.isNewline }.compactMap { String($0) }

let wire1 = wires[0].split(separator: ",").compactMap{ String($0) }
let wire2 = wires[1].split(separator: ",").compactMap{ String($0) }



let wire1Movement = ["R8","U5","L5","D3"]
let wire2Movement = ["U7","R6","D4","L4"]

struct Coordinate: Hashable {
    var x,y: Int
}

extension Coordinate: Equatable {
    static func == (lhs: Coordinate, rhs: Coordinate) -> Bool {
        return lhs.x == rhs.x &&
            lhs.y == rhs.y
    }
}

extension Coordinate: CustomStringConvertible {
    var description: String {
        return "(\(x), \(y))"
    }
}



func buildSet(wireMovement: [String]) -> (Set<Coordinate>, [Coordinate:Int]) {
    var allCoordinates = Set<Coordinate>()

    var currentPosition = Coordinate(x: 0, y: 0)
    var numberOfSteps = [Coordinate:Int]()
    var totalSteps = 0

    for move in wireMovement {
        guard let movement = Movement(rawValue: move.first!),
            let distance = Int(String(move.dropFirst())) else { fatalError() }

        print(movement, distance)
        switch movement {
        case .right:
            for _ in 0..<distance{
                totalSteps += 1
                currentPosition.x += 1
                numberOfSteps[currentPosition] = totalSteps
//                print("Position: ", currentPosition, "Total Steps: ", totalSteps)
                allCoordinates.insert(currentPosition)
            }
        case .up:
            for _ in 0..<distance{
                totalSteps += 1
                currentPosition.y += 1
                numberOfSteps[currentPosition] = totalSteps
//                print("Position: ", currentPosition, "Total Steps: ", totalSteps)
                allCoordinates.insert(currentPosition)
            }
        case .left:
            for _ in 0..<distance{
                totalSteps += 1
                currentPosition.x -= 1
                numberOfSteps[currentPosition] = totalSteps
// print("Position: ", currentPosition, "Total Steps: ", totalSteps)
                allCoordinates.insert(currentPosition)
            }
        case .down:
            for _ in 0..<distance{
                totalSteps += 1
                currentPosition.y -= 1
                numberOfSteps[currentPosition] = totalSteps
// print("Position: ", currentPosition, "Total Steps: ", totalSteps)
                allCoordinates.insert(currentPosition)
            }
        }
    }

    return (allCoordinates, numberOfSteps)
}

enum Movement: Character {
    case right = "R"
    case up = "U"
    case left = "L"
    case down = "D"
}


//R75,D30,R83,U83,L12,D49,R71,U7,L72
//U62,R66,U55,R34,D71,R55,D58,R83

//let (set1, steps1) = buildSet(wireMovement:
//    ["R75","D30","R83","U83","L12","D49","R71","U7","L72"])
//let (set2, steps2) = buildSet(wireMovement: ["U62","R66","U55","R34","D71","R55","D58","R83"])

func findTotalSteps(for set1: Set<Coordinate>, set2: Set<Coordinate>, steps1: [Coordinate:Int], steps2:[Coordinate:Int]){
    let intersections  = set1.intersection(set2)

    var fewestSteps = Int.max
    for intersection in intersections {
        print(steps1[intersection])
        print(steps2[intersection])

        fewestSteps = min(fewestSteps, steps1[intersection]! + steps2[intersection]!)
    }

    print("Fewest Steps: ", fewestSteps)
}

//findTotalSteps(for: set1, set2: set2, steps1: steps1, steps2: steps2)


//let (se1, _) = buildSet(wireMovement: wire1Movement)
//let (se2, _) = buildSet(wireMovement: wire2Movement)
//
//let a = se1.intersection(se2)
//print(a)

// Solution

let (set1, steps1) = buildSet(wireMovement: wire1)
let (set2, steps2) = buildSet(wireMovement: wire2)

//let (set1, steps1) = buildSet(wireMovement: ["R98","U47","R26","D63","R33","U87","L62","D20","R33","U53","R51"])
//let (set2, steps2) = buildSet(wireMovement: ["U98","R91","D20","R16","D67","R40","U7","R15","U6","R7"])
findTotalSteps(for: set1, set2: set2, steps1: steps1, steps2: steps2)