[Advent Of Code 2022] Day 06: Tuning Trouble [SPOILERS]

Programming
1

Another relatively quick and easy one. Supposedly Eric said he likes putting easy days around hard days.

Something tells me we’re going to see more data streams in the near future!

Python. Rough code. Tidied code

Python Solution 
    def find_unique_n_start(self, line: str, num: int) -> int:
        parts = [line[i:] for i in range(num)]
        for offset, chars in enumerate(zip(*parts)):
            if len(set(chars)) == num:
                return offset + num

    def part1(self, parsed_input: InputType) -> int:
        return self.find_unique_n_start(parsed_input, 4)

    def part2(self, parsed_input: InputType) -> int:
        return self.find_unique_n_start(parsed_input, 14)
1 Like
2

I was so focused on an efficient solution that it took me a while to get to this

Python solution 
def find_unique_sequence_start(data: str, size: int) -> int:
    """Find the first substring of given `size` with unique chars."""
    current_size, last_seen = 0, {}
    for idx, char in enumerate(data, 1):
        prev_idx = last_seen.get(char, idx - current_size - 1)
        current_size = min(current_size + 1, idx - prev_idx)
        if current_size == size:
            return idx
        last_seen[char] = idx
    return -1

In hindsight I should have realized that the puzzle was small enough that a simpler and less efficient approach would have sufficient and faster to write.

BTW: @IsaacG How do you get the details tag and the syntax highlighting?

3

I nest them :grin: I make a details section then manually add backticks inside of it.

4

Strange. I do the same, but I don’t get the hightlighting:

<details>
<summary>Python solution</summary>

```py
size = 14
return next(i
        for i, window in enumerate(more_itertools.sliding_window(data, size), size)
        if len(set(window)) == size)
```

</details>
Python solution 
return next(i
        for i, window in enumerate(more_itertools.sliding_window(data, size), size)
        if len(set(window)) == size)
1 Like
5 
[details="Python Solution"]
\```python
...
\```
[/details]
6

Thank you very much!

7
Ruby Solution 
def marker(size) = File.read('inputs/06.txt').chars.each_cons(size).find_index { |chars| chars.uniq.size == size } + size

a = marker(4)
b = marker(14)
8

Another easy one, still enjoyed it.

Typescript solution

I considered building a custom set that would keep a counter of the items seen
and would remove them if the counter is 0, but I figured it’s probably not worth it. Re-creating the set every time seems fast enough, part 2 takes just 3 ms, part 1 is < 1 ms, so I’m not too fussed about it.

interface State {
  signal: string;
}

export function parse(input: string): State {
  return { signal: nonEmptyLines(input)[0] };
}

export function part1(parsed: State): string {
  return seekMarker(parsed.signal, 4).toString();
}

export function part2(parsed: State): string {
  return seekMarker(parsed.signal, 14).toString();
}

export function seekMarker(signal: string, markerSize: number): number {
  for (let i = markerSize; i < signal.length; i += 1) {
    const lastX = signal.slice(i - markerSize, i);
    if (lastX.length === new Set(lastX).size) {
      return i;
    }
  }
  return NaN;
}
9
Quick Put Something Down ... Anything! Julia Solution 
module day06
    function part01() 
        input = readchomp("/Users/anagy/Documents/AdventOfCode2022/AdventOfCode2022-Julia/input/06/input.in")
​
        count = 4
        lastSeen = collect(input[1:4])
​
        for c in input[5:end]
            lastSeen = lastSeen[2:end]
            append!(lastSeen, c)
            count += 1
            if length(unique(lastSeen)) == 4
                break
            end
        end
        count
    end
​
    function part02()
        input = readchomp("/Users/anagy/Documents/AdventOfCode2022/AdventOfCode2022-Julia/input/06/input.in")
​
        count = 14
        lastSeen = collect(input[1:14])
​
        for c in input[15:end]
            lastSeen = lastSeen[2:end]
            append!(lastSeen, c)
            count += 1
            if length(unique(lastSeen)) == 14
                break
            end
        end
        count
    end
end
​
​
println("P01: $(day06.part01())")
println("P02: $(day06.part02())")
Prettified Julia Solution 
module day06
    function part01() 
        input = readchomp("/Users/anagy/Documents/AdventOfCode2022/AdventOfCode2022-Julia/input/06/input.in")

        findfirst(i -> allunique(input[i:i+4-1]), 1:length(input)) + 4 - 1
    end

    function part02()
        input = readchomp("/Users/anagy/Documents/AdventOfCode2022/AdventOfCode2022-Julia/input/06/input.in")

        findfirst(i -> allunique(input[i:i+14-1]), 1:length(input)) + 14 - 1
    end
end


println("P01: $(day06.part01())")
println("P02: $(day06.part02())")