Advent of Code

[tonycollinet]

Day 5 relatively trivial.

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input_file = open("5aInput.txt", "r")
#input_as_list = [(line.strip()).split() for line in input_file]
input_as_list = [line.strip() for line in input_file]
input_file.close()


max_id = 0
min_id = 1024
ids = []
for ticket in input_as_list:
    id = 0
    for bitnum in range (10):
        index = 9 - bitnum
        bit = ticket[index]
        if bit =="B" or bit == "R":id += 2 ** bitnum
    if id > max_id: max_id = id
    if id < min_id: min_id = id
    ids.append(id)
   
print (min_id, max_id)

for id in range (min_id, max_id):
    if not id in ids: print ("Missing ID is ", id)

EDIT: or more efficiently with direct conversion...

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to binary:


input_file = open("5aInput.txt", "r")
#input_as_list = [(line.strip()).split() for line in input_file]
input_as_list = [line.strip() for line in input_file]
input_file.close()


max_id = 0
min_id = 1024
ids = []
for ticket in input_as_list:
    ticket = ticket.replace("B","1")
    ticket = ticket.replace("F","0")
    ticket = ticket.replace("R","1")
    ticket = ticket.replace("L","0")
    id = int(ticket,2)

    if id > max_id: max_id = id
    if id < min_id: min_id = id
    ids.append(id)
   
print (min_id, max_id)

for id in range (min_id, max_id):
    if not id in ids: print ("Missing ID is ", id)

[grams]

Day 5 probably the easiest spreadsheet yet:
https://docs.google.com/spreadsheets/d/1urBVcFFAz4HzJshKldFKtgobE_Zi8DGGNgY4Na5ATHw/edit?usp=sharing

[Pingu]

Day 5 probably the easiest spreadsheet yet:
https://docs.google.com/spreadsheets/d/1urBVcFFAz4HzJshKldFKtgobE_Zi8DGGNgY4Na5ATHw/edit?usp=sharing

Loving the spreadsheet solutions You are Dido Harding AICMFP 

[tonycollinet]

Day 5 probably the easiest spreadsheet yet:
https://docs.google.com/spreadsheets/d/1urBVcFFAz4HzJshKldFKtgobE_Zi8DGGNgY4Na5ATHw/edit?usp=sharing

So - your data set is different than mine - bigger even. Does that mean each participant gets their own data?

[Pingu]

Day 5 probably the easiest spreadsheet yet:
https://docs.google.com/spreadsheets/d/1urBVcFFAz4HzJshKldFKtgobE_Zi8DGGNgY4Na5ATHw/edit?usp=sharing

So - your data set is different than mine - bigger even. Does that mean each participant gets their own data?

Yes

[tonycollinet]

That is very cool.

The creators obviously put a lot of work into that.

[Greenbank]

Day 6 was nowhere near as difficult as I expected.

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Luckily the way I'd chosen to implement part 1 made adapting it for part 2 relatively easy.

(This doesn't often happen, so I'll take it.)

I'd read in each group and incremented an entry in a hash for each letter that was contained in the hash.

Part 1 was simply summing the number of keys in the hash each time (and clearing the hash between groups).

For part 2 I just had to add a count the number of people in the group (the number of lines that made it up) and then count the number of keys in the hash that were the same as the number of people in the group.

Both answers correct first time too.

Also a simple "grep "[^a-z]" 6.inp" showed me there were no characters other than lower case a-z and so I didn't have to bother with any code to deal with unexpected situations. That and checking the last line was a blank line so that the last group wasn't forgotten about (if I only kicked off the processing when reading in a blank line).

[tonycollinet]

Day 6 complete.

I have to say Python has an incredibly rich set of functionality. Almost every operation I need to do has a pre-defined method.

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input_file = open("6aInput.txt", "r")
#input_as_list = [(line.strip()).split() for line in input_file]
input_as_list = [line.strip() for line in input_file]
input_file.close()

groups = []
group = []
sumCountsAny = 0
sumCountsAll = 0

for line in input_as_list:
    if len (line)==0:
        groups.append (group)
        group = []
    else:
        group.append (line)
           
groups.append (group)   

# Any person answered question yes
# for group in groups:
#     groupSummarised = "".join(set("".join(group)))
#     sumCountsAny += len (groupSummarised)
#     print (group, groupSummarised, len (groupSummarised),sumCountsAny)
   
# All people answered question yes
for group in groups:
    groupSummarisedSet = set.intersection(*[set(x) for x in group])
    sumCountsAll += len (groupSummarisedSet)
    print (group, groupSummarised, len (groupSummarised),sumCountsAll)
   
print (sumCountsAny, sumCountsAll)

[grams]

Day 6: Still spreadsheeting
https://docs.google.com/spreadsheets/d/1VXcXG-N5KLMXUIs0Tdb7ObusNgZVVFaLnjdTCfD4AsA/edit?usp=sharing

I cocked up this time because this is the first dataset that's longer than 1000 lines (Google Sheets default size) and I handed bothered filling down my formulae.

[Pingu]

Day 6 done.

http://www.pinniped.plus.com/AoC/index.htm

[grams]

Day 7:

Spent much longer wrestling with the shitty lookup functions (VLOOKUP and MATCH) then I did with making recursion work.

https://docs.google.com/spreadsheets/d/11cUvSGYl9NT2-3prdotWaXyiD_-DfIFLJmeRujuxXwQ/edit?usp=sharing

[Greenbank]

Luckily part 2 didn't ask about the shiny purple bag:

BAG: shiny purple = 365714937810

Still waiting for a humdinger.

[Davef]

Just done days 2 through 7. Not very exciting so far.

[Pickled Onion]

Just done 2016 day 11. Had a mental block on it at the time, not sure why, it was fairly straightforward when I actually started coding it, with some interesting puzzles over optimisation.

[tonycollinet]

Well, as a relative novice, today had me scratching my head a little.

Getting head around recursion is tricky. I also had a function return statement that prevented the function processing anything other than the first "subbag" - which took nearly an hour to find.

Even just working out how to parse the input takes some time if you've never done it before.

Still - got there in the end.

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def bagContains (bag, bagName):
    for subbag in bag [1:]:
        if subbag[1]==bagName:
            return True
    return False
   

containingBags = []
def findContainingBags (bagName):
    count = 0
    countSG = 0
    for bag in bags:
        if bagContains (bag, bagName):
            containingBags.append(bag[ 0 ] )
            count += 1
            count += findContainingBags (bag[ 0 ] )
    return count

def countBagsInside (bagname):
    count = 0
    for bag in bags:
        if bag[0] == bagname:
            for subbag in bag [1:]:
                count += int (subbag [ 0 ] )         
                count += int (subbag [ 0 ] ) * countBagsInside (subbag [1] )
    return count           

input_file = open("7aInput.txt", "r")
#input_as_list = [(line.strip()).split() for line in input_file]
input_as_list = [line.strip() for line in input_file]
input_file.close()


bags = []

#parse input into bag list structure
for line in input_as_list:
    bag = []
    subbags = []
    bag.append(line.split(" bags contain ")[0])
    subbags= (line.split(" bags contain ")[1].split(", "))
    for subbag in subbags:
        subbag = subbag.replace(".","")
        subbag = subbag.replace(" bags","")
        subbag = subbag.replace(" bag","")
        subbag = subbag.replace("no","0")
        bag.append (subbag.split(" ",1))   
    bags.append (bag)
   
dummy = findContainingBags ("shiny gold")
print ("Part 1: Number of bags containing a shiny gold bag is", len(set(containingBags)))

print ("Part 2: Total bags inside a shiny gold bag is ", countBagsInside ("shiny gold"))

[Davef]

A little more interesting today. I can see there could be some fun ahead.

[Greenbank]

Indeed, the beginnings of the VM.

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I'll probably spin out the execution code to a separate source file that can be included by future days.

I'll include a bunch of other stuff that might come up, such as input/output queues, ability to execute multiple instances of the VM at once, etc

These are all things that have come up in previous years.

[Davef]

I was thinking Gödel’s incompleteness theorem and the Turing halting problem. It might inspire you to go back to your bookshelf.

[Ben T]

I bloody hate these ones where you have to try and reverse engineer the machine code to find out what it's doing. For day 8 it was quite easy to test whether it's an infinite loop or not, as the program is effectively immutable. It's the ones where it jumps by the amount of a variable that are annoying.

[Greenbank]

I kind of like this ones.

I end up rewriting it in something like perl and then replacing the instructions/jumps/branches with higher level constructs (while loops, for loops, etc) and then working out what the code is doing (such as painfully slowly implementing Eulers totient or phi function or similar).

[Greenbank]

I was thinking Gödel’s incompleteness theorem and the Turing halting problem. It might inspire you to go back to your bookshelf.

And my degree(s). I did a fair bit on both of those in each of them.

Looking forward to some other problems like:-
* a big nasty number theory problem (like the Chinese Remainder Theorem inspired one [2017 day 13], or the famous Space Cards [2019 day 22]).
* an A* or SAT style solver
* ...probably in a maze of some sort
* Writing something to interactively play a game (like Breakout [2019 day 13])
* A 3D (or even 4D) problem

[Ben T]

I kind of like this ones.

I end up rewriting it in something like perl and then replacing the instructions/jumps/branches with higher level constructs (while loops, for loops, etc) and then working out what the code is doing (such as painfully slowly implementing Eulers totient or phi function or similar).

I'll usually just leave it grinding away in C++ on my old ubuntu laptop unless it's literally going to take years. 

[grams]

Day 8 done:
https://docs.google.com/spreadsheets/d/1QLnJ--jc1d18qHiwcO1QXnqyaoG078-09HlYiXvoA_0/edit#gid=1072555748

I started doing part 2 by inspection, but that seemed against the spirit of it. So executed it 500 times in one spreadsheet instead. Fan is still spinning.

[tonycollinet]

Day 8 done.

Quite liked this one - though tied myself up with failing to modify global variables in a function. Eventually found the "global" statement.

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executed multiple runs, incrementing the code address at which the instruction would be changed each run. Later halved the number of runs by starting at the maximum address, and decrementing that each run.

I could reduce it further by checking the selected address is nop or jmp, but can't be bothered 

******
def resetProgram():
    global addr
    global acc
    global program
   
    addr = 0
    acc = 0
    for index, code in enumerate (program):
        program [index][2] = 0
       

input_file = open("8aInput.txt", "r")
#input_as_list = [(line.strip()).split() for line in input_file]
input_as_list = [line.strip() for line in input_file]
input_file.close()


program = []

#parse input into program memory - third item of line is instruction execution count
for line in input_as_list:
    codeLine = []
    codeLine = [line.split(" ")[0],int(line.split(" ")[1]), 0]
    program.append (codeLine)

addr = 0
acc = 0
addrToChange = len(program) - 1
runcount = 0

#Execute program
while addr < len(program):
# setup instruction

    inst = program[addr][0]
    if addr == addrToChange:
        if inst == "nop" :
            inst = "jmp"
            print ("address ",addr, "nop changed to jmp")
        elif inst == "jmp" :
            inst = "nop"
            print ("address ",addr, "jmp changed to nop")
    param = program[addr][1]


#check for pass termination or execute instruction
    program[addr][2]+=1
    if program[addr][2] > 1:
        print (acc, runcount, addrToChange)   
        resetProgram()
        runcount +=1
        addrToChange -=1
    else:   
    #execute instruction     
        if inst == "jmp": addr+= param
        elif inst == "acc":
            acc+= param
            addr+=1
        else:
            addr+=1

       
print (acc)

[Greenbank]

Day 9 underwhelming.

Lucky as I've got a busy day.