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Refactor

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This commit is contained in:
Sven Weidauer 2020-12-14 19:02:48 +01:00
parent db394f7e14
commit 1caa6bda84
1 changed files with 56 additions and 55 deletions
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111
day14/main.swift
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@ -1,56 +1,68 @@
import Foundation
let scanner = Scanner(string: loadData(day: 14))
let input = loadData(day: 14)
class Problem {
let scanner: Scanner
/// Each bit where the mask is "1" is set here
var maskBits: UInt64 = 0
/// Each bit where the mask is "X" is set here
var maskUsed: UInt64 = 0
var mem: [UInt64:UInt64] = [:]
var writeMem: (Problem, UInt64, UInt64) -> Void
init(_ input: String, writeMem: @escaping (Problem, UInt64, UInt64) -> Void) {
scanner = Scanner(string: input)
self.writeMem = writeMem
}
func run() {
while !scanner.isAtEnd {
if scanner.string("mask = "), let mask = scanner.scanCharacters(from: Self.maskSet) {
readMask(mask)
} else if scanner.string("mem["), let addr = scanner.scanUInt64(), scanner.string("] = "), let value = scanner.scanUInt64() {
writeMem(self, addr, value)
} else {
assertionFailure("Invalid input")
}
}
var maskBits: UInt64 = 0
var maskUsed: UInt64 = 0
print("sum", mem.values.reduce(0, +))
}
private func readMask(_ mask: String) {
assert(mask.count == 36)
var mem: [UInt64:UInt64] = [:]
maskBits = 0
maskUsed = 0
for char in mask {
maskBits <<= 1
maskUsed <<= 1
func readMask(_ mask: String) {
assert(mask.count == 36)
maskBits = 0
maskUsed = 0
for char in mask {
maskBits <<= 1
maskUsed <<= 1
switch char {
case "1": maskBits |= 1
case "0": break
case "X": maskUsed |= 1
default: assertionFailure("Invalid character in mask")
switch char {
case "1": maskBits |= 1
case "0": break
case "X": maskUsed |= 1
default: assertionFailure("Invalid character in mask")
}
}
}
static private let maskSet = CharacterSet(charactersIn: "01X")
}
func applyMask(_ value: UInt64) -> UInt64 {
(value & maskUsed) | maskBits
let part1 = Problem(input) { problem, addr, value in
problem.mem[addr] = (value & problem.maskUsed) | problem.maskBits
}
let maskSet = CharacterSet(charactersIn: "01X")
/*
while !scanner.isAtEnd {
if scanner.string("mask = "), let mask = scanner.scanCharacters(from: maskSet) {
readMask(mask)
} else if scanner.string("mem["), let addr = scanner.scanInt(), scanner.string("] = "), let value = scanner.scanUInt64() {
mem[addr] = applyMask(value)
} else {
assertionFailure("Invalid input")
}
}
*/
part1.run()
func printPadded(_ val: UInt64) {
let s = String(val, radix: 2)
print(String(repeating: " ", count: 36 - s.count) + s)
}
func possibleValues(_ mask: UInt64) -> [UInt64] {
var values: [UInt64] = []
@ -71,22 +83,11 @@ func possibleValues(_ mask: UInt64) -> [UInt64] {
return values
}
func writeMem(_ addr: UInt64, _ value: UInt64) {
for i in possibleValues(maskUsed) {
let effective = i | ((addr | maskBits) & ~maskUsed)
mem[effective] = value
let part2 = Problem(input) { problem, addr, value in
for i in possibleValues(problem.maskUsed) {
let effective = i | ((addr | problem.maskBits) & ~problem.maskUsed)
problem.mem[effective] = value
}
}
while !scanner.isAtEnd {
if scanner.string("mask = "), let mask = scanner.scanCharacters(from: maskSet) {
readMask(mask)
} else if scanner.string("mem["), let addr = scanner.scanUInt64(), scanner.string("] = "), let value = scanner.scanUInt64() {
writeMem(addr, value)
} else {
assertionFailure("Invalid input")
}
}
print("sum", mem.values.reduce(0, +))
part2.run()