AoC/2019/AoC.playground/Pages/Day 5.xcplaygroundpage/Contents.swift

let program = [3,225,1,225,6,6,1100,1,238,225,104,0,1002,36,25,224,1001,224,-2100,224,4,224,1002,223,8,223,101,1,224,224,1,223,224,223,1102,31,84,225,1102,29,77,225,1,176,188,224,101,-42,224,224,4,224,102,8,223,223,101,3,224,224,1,223,224,223,2,196,183,224,1001,224,-990,224,4,224,1002,223,8,223,101,7,224,224,1,224,223,223,102,14,40,224,101,-1078,224,224,4,224,1002,223,8,223,1001,224,2,224,1,224,223,223,1001,180,64,224,101,-128,224,224,4,224,102,8,223,223,101,3,224,224,1,223,224,223,1102,24,17,224,1001,224,-408,224,4,224,1002,223,8,223,101,2,224,224,1,223,224,223,1101,9,66,224,1001,224,-75,224,4,224,1002,223,8,223,1001,224,6,224,1,223,224,223,1102,18,33,225,1101,57,64,225,1102,45,11,225,1101,45,9,225,1101,11,34,225,1102,59,22,225,101,89,191,224,1001,224,-100,224,4,224,1002,223,8,223,1001,224,1,224,1,223,224,223,4,223,99,0,0,0,677,0,0,0,0,0,0,0,0,0,0,0,1105,0,99999,1105,227,247,1105,1,99999,1005,227,99999,1005,0,256,1105,1,99999,1106,227,99999,1106,0,265,1105,1,99999,1006,0,99999,1006,227,274,1105,1,99999,1105,1,280,1105,1,99999,1,225,225,225,1101,294,0,0,105,1,0,1105,1,99999,1106,0,300,1105,1,99999,1,225,225,225,1101,314,0,0,106,0,0,1105,1,99999,8,226,677,224,1002,223,2,223,1006,224,329,1001,223,1,223,108,226,226,224,1002,223,2,223,1006,224,344,1001,223,1,223,7,677,226,224,102,2,223,223,1005,224,359,101,1,223,223,7,226,677,224,102,2,223,223,1006,224,374,101,1,223,223,1008,677,226,224,1002,223,2,223,1006,224,389,101,1,223,223,8,677,677,224,1002,223,2,223,1005,224,404,101,1,223,223,8,677,226,224,102,2,223,223,1005,224,419,1001,223,1,223,1107,677,226,224,102,2,223,223,1005,224,434,1001,223,1,223,1107,226,677,224,1002,223,2,223,1006,224,449,1001,223,1,223,107,677,226,224,1002,223,2,223,1005,224,464,1001,223,1,223,1008,677,677,224,1002,223,2,223,1006,224,479,1001,223,1,223,1108,677,226,224,1002,223,2,223,1006,224,494,1001,223,1,223,1108,677,677,224,1002,223,2,223,1006,224,509,1001,223,1,223,107,677,677,224,1002,223,2,223,1005,224,524,101,1,223,223,1007,677,226,224,102,2,223,223,1005,224,539,1001,223,1,223,1107,226,226,224,1002,223,2,223,1006,224,554,1001,223,1,223,1008,226,226,224,1002,223,2,223,1006,224,569,101,1,223,223,1108,226,677,224,1002,223,2,223,1006,224,584,101,1,223,223,108,677,677,224,1002,223,2,223,1006,224,599,1001,223,1,223,1007,677,677,224,102,2,223,223,1006,224,614,101,1,223,223,107,226,226,224,102,2,223,223,1006,224,629,101,1,223,223,1007,226,226,224,102,2,223,223,1005,224,644,1001,223,1,223,108,226,677,224,102,2,223,223,1005,224,659,1001,223,1,223,7,677,677,224,102,2,223,223,1006,224,674,1001,223,1,223,4,223,99,226]


func input() -> Int {
    return 5
}

func output(_ value: Int) {
    print("output>",value)
}

func pow(base: Int = 10, _ n: Int) -> Int {
    precondition( n >= 0 )
    switch n {
    case 0: return 1
    case 1: return base
    case _ where n.isMultiple(of: 2):
        return pow(base: base * base, n / 2)
    default:
        return base * pow(base: base * base, n / 2)
    }
}

func run() {
    var memory = program

    var pc = 0

    func get(_ index: Int) -> Int {
        let mode = (memory[pc] / pow(2 + index - 1)) % 10

        switch mode {
        case 0: return memory[memory[pc + index]]
        case 1: return memory[pc + index]
        default: preconditionFailure("Unknown mode \(mode)")
        }
    }

    func put(_ index: Int, value: Int) {
        memory[memory[pc + index]] = value
    }

    loop: while(true) {
        let opcode = memory[pc] % 100

        print("pc", pc, "op", opcode)

        switch opcode {
        case 1:
            put(3, value: get(1) + get(2))
            pc += 4

        case 2:
            put(3, value: get(1) * get(2))
            pc += 4

        case 3:
            put(1, value: input())
            pc += 2

        case 4:
            output(get(1))
            pc += 2

        case 5:
            if get(1) != 0 {
                pc = get(2)
            } else {
                pc += 3
            }

        case 6:
            if get(1) == 0 {
                pc = get(2)
            } else {
                pc += 3
            }

        case 7:
            put(3, value: get(1) < get(2) ? 1 : 0)
            pc += 4

        case 8:
            put(3, value: get(1) == get(2) ? 1 : 0)
            pc += 4

        case 99:
            break loop

        default:
            preconditionFailure("Unknown opcode \(opcode)")

        }
    }
}

run()