Hi, I'm in Day7 part 1. I have the right algo for ...

# advent-of-code

[Jérôme Gully]

Hi, I'm in Day7 part 1. I have the right algo for the example input, but not with the real input, I didn't see how to investigate that, other people having the same issue ? What I have missed ?

[bjonnh]

show us your code

[Jérôme Gully]

Are you sure ? it's a big mess at the moment 😄

[Jérôme Gully]

fun String.asBags(): HashMap<String, List<String>> {
    val bags = hashMapOf<String, List<String>>()

    lines().filterNot { it.endsWith("no other bags.") }
        .filterNot { it.startsWith("shiny gold") }
        .also { println("size ${it.size}") }
        .forEach { line ->
            val (bagName, children) = line.split(" bags contain ")
            val childrenList = children.dropLast(1)
                .split(", ")
                .map { bag -> bag.drop(2) }
                .map { it.replace(" bags", "").replace(" bag", "") }
            bags += bagName to childrenList
        }
    return bags
}

This is for the data structure creation

[adamratzman]

Otherwise, not sure we can help you

[Jérôme Gully]

fun isShinyInside(bagName: String, bags: HashMap<String, List<String>>): Boolean {
    println("next bag name: $bagName")
    val children = bags[bagName]
    if (children?.any { child -> child == "shiny gold" } == true) {
        println(" ** shiny found **")
        return true
    } else {
        println("no shiny found, go deeper")
        indent++
        children?.forEach { child ->
            return isShinyInside(child, bags)
        }
    }
    return false
}

Recursive part

[adamratzman]

can you just send the entire file @Jérôme Gully

[Jérôme Gully]

@Test
fun `sum of shiny gold bags`() {
    val bags = realInput.asBags()
    val sum = bags.keys.sumBy { bagName ->
        if (isShinyInside(bagName, bags)) 1 else 0
    }
    println("Part A: $sum")
}

Use real input with isShinyInside to count shiny gold

[Jérôme Gully]

Yep sorry

[Jérôme Gully]

class Day7 {

    @Nested
    inner class PartA {

        @Nested
        inner class `Example data` {
            @Test
            fun `assert sum of shiny gold bags is 4`() {
                val bags = exampleInput.asBags()
                val sum = bags.keys.sumBy { bagName ->
//            println("loop $bagName")
                    if (isShinyInside(bagName, bags)) 1 else 0
                }
                assertEquals(4, sum)
            }
        }

        @Nested
        inner class `Real data` {
            @Test
            fun `sum of shiny gold bags`() {
                val bags = realInput.asBags()
                val sum = bags.keys.sumBy { bagName ->
                    if (isShinyInside(bagName, bags)) 1 else 0
                }
                println("Part A: $sum")
            }
        }
    }

    fun isShinyInside(bagName: String, bags: HashMap<String, List<String>>): Boolean {
        println("next bag name: $bagName")
        val children = bags[bagName]
        if (children?.any { child -> child == "shiny gold" } == true) {
            println(" ** shiny found **")
            return true
        } else {
            println("no shiny found, go deeper")
            children?.forEach { child ->
                return isShinyInside(child, bags)
            }
        }
        return false
    }

//    data class Bag(val name: String, val childrenBags: List<Bag> = emptyList(), var count: Int = 1)

    fun String.asBags(): HashMap<String, List<String>> {
        val bags = hashMapOf<String, List<String>>()

        lines().filterNot { it.endsWith("no other bags.") }
            .filterNot { it.startsWith("shiny gold") }
            .also { println("size ${it.size}") }
            .forEach { line ->
                val (bagName, children) = line.split(" bags contain ")
                val childrenList = children.dropLast(1)
                    .split(", ")
                    .map { bag -> bag.drop(2) }
                    .map { it.replace(" bags", "").replace(" bag", "") }
                bags += bagName to childrenList
            }
        return bags
    }
}

I used the test approach, I ommited the companion object with input

[Jérôme Gully]

Sorry for your eyes, this code is so dirty 🙃

[bjonnh]

are you using the number of bags anywhere?

[Jérôme Gully]

no, I should ?

[Jérôme Gully]

I guessed it's for part B

[bjonnh]

oh yeah sorry

[bjonnh]

children?.forEach { child ->
            return isShinyInside(child, bags)
        }

not sure that's right

[bjonnh]

that mean if it is not in the first child, you return false

[adamratzman]

yes

[bjonnh]

but what you want is to continue checking

[bjonnh]

(I'll let you work that solution, come back here if you have trouble}

[adamratzman]

fixing that will solve your issue 😄 just checked

[Jérôme Gully]

Ho yes right, thanks !

[Jérôme Gully]

Yeah I will try to fix and clean it up, it's a shame to share a code like that 😂

[adamratzman]

you could even simplify that function further to

fun isShinyInside(bagName: String, bags: HashMap<String, List<String>>): Boolean {
    val children = bags[bagName]
    return bagName == "shiny gold" || children != null && 
            (children.any { child -> child == "shiny gold" } || children.any { child -> isShinyInside(child, bags) })
}

[bjonnh]

not all code is born beautiful

[Jérôme Gully]

yeah I changed forEach for any, i must wait 1 minute to submit the answer, 🤞

[Jérôme Gully]

I like all the smart collections function we have, but in my day to day work i'm not used to use it a lot

[Jérôme Gully]

true @bjonnh I try to have a simple/dirty code working, and after I refactor. Well the code above did not pass the second step 😂

[Jérôme Gully]

Yeah thanks was that, part A validated

[bjonnh]

if you try to optimize too early you may not be able to do part2 without redoing everything anyway

[bjonnh]

2015 day 9 part 2 took me a few seconds yesterday

[bjonnh]

I just had to write out.maxOrNull() instead of out.minOrNull()

[adamratzman]

I had to write out another function for part 2 but the idea was similar, so did not take long

[Jérôme Gully]

Thanks for your code @adamratzman I will analyse it when I finish the day 7, erf for day 8 there is only one hour left for France till midnight, I'm late ^^

[Jérôme Gully]

Something is easyer/faster to copy/past solution part A and adapt it a bit for part B yeah

[bjonnh]

oh this I never do

[bjonnh]

I just keep my data structures not too optimized (keeping all values, arguments etc)

[bjonnh]

for example in the case of the bags

[bjonnh]

since part1 my data structure contained the numbers

[bjonnh]

sometimes it is not used, but when it is used, you gain valuable time

[adamratzman]

yeah I did that too