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kajottkajott
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added 2022/03-04, and x86 DOS assembly for 2022/02
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‎.gitignore

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a.o
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*vis*.p[gp]m
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*.com
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*.lst
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*.OUT

‎2022/02/README.md

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* Part 1, Python: 101 bytes, <100 ms
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* Part 2, Python: 91 bytes, <100 ms
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* Parts 1+2, x86 DOS Assembly: 183 bytes (assembled)

‎2022/02/aoc2022_02.asm

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; yasm -fbin -oaoc22_02.com aoc2022_02.asm && dosbox aoc22_02.com
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; yasm -fbin -oaoc22_02.com aoc2022_02.asm && dosbox -c "mount c: ." -c "c:" -c "td aoc22_02.com"
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BITS 16
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CPU 8086
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ORG 100h
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; open file
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mov ax, 3D00h ; DOS function "open file" (for reading)
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mov dx, file
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int 21h
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jc io_err
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mov bx, ax ; save file handle for next operation
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; read file contents into the (nearly) 64k of empty space in this .COM file
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mov ah, 3Fh ; DOS function "read file"
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mov cx, 0FF00h ; read as much as we (somewhat) safely can
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sub cx, dx
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int 21h
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jnc io_ok
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io_err:
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mov ax, 4C01h ; DOS function "terminate program" (with exit code 1)
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int 21h
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io_ok:
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mov si, dx ; store address of 'file' variable for later
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add dx, ax ; append null terminator to end of file data
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mov di, dx
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mov byte [di], 0
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; close file (optional - the OS will clean up our mess too, if needed :)
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; mov ah, 3Eh ; DOS function "close file"
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; int 21h
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; now iterate over the input file
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nextchar:
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lodsb ; load a byte
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or al, al ; EOF reached?
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jz eof
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cmp al, 'C' ; is is possibly an XYZ value?
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ja .maybe_xyz
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sub al, 'A' ; not XYZ -> check for ABC (and map to ABC=012)
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cmp al, 3
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jae nextchar ; not a valid character
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inc al ; save decoded ABC value (mapped to ABC=123)
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mov ah, al
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jmp nextchar
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.maybe_xyz:
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sub al, 'X' ; check for XYZ (and map to XYZ=012)
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cmp al, 3
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jae nextchar ; not a valid character
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push ax ; save original result (will be clobbered in part 1 evaluation)
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; part 1: check if we have won
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xor cx, cx ; reset score
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inc al ; remap our result to XYZ=123
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cmp ah, al ; draw?
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je .p1_draw
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inc ah ; correct_guess = opponents_guess + 1
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cmp ah, 4 ; ... with wrap-around
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jb .p1_nowrap
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sub ah, 3
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.p1_nowrap:
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cmp ah, al ; won?
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jne .p1_finish ; if not, just add score
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add cl, 3 ; add 3 (of 6) points for win
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.p1_draw:
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add cl, 3 ; add 3 points for draw (or another 3 points for win)
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.p1_finish:
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add cl, al ; add score for local player's choice
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add [part1], cx ; add to accumulator
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; part 2: create a suitable score
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pop ax ; restore the original input data
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xor cx, cx ; reset score
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add cl, al ; ... and set to 3 * winning_indicator
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add cl, al
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add cl, al
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add al, 2 ; convert winning_indicator to offset: lose=2, draw=3(=0 mod 3), win=4(=1 mod 3)
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add al, ah ; ... and add offset to opponent's choice to get our choice
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.p2_wrapcheck:
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cmp al, 4 ; check for wrap-around
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jb .p2_nowrap
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sub al, 3
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jmp .p2_wrapcheck
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.p2_nowrap:
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add cl, al ; add score for local player's choice
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add [part2], cx ; add to accumulator
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jmp nextchar ; continue with next input character
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eof:
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mov ax, [part1]
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call OutputWord
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mov ax, [part2]
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; now run right into the OutputWord function which will also exit the program
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; -----------------------------------------------------------------------------
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; FUNCTION: OutputWord - output a word in decimal onto the screen
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; in AX = word to output
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; clobbers BX, CX, DX
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OutputWord:
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; add terminating EOL to output stack
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mov bl, 0Ah
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push bx
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mov bl, 0Dh
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push bx
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.nextdigit:
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mov bx, 10 ; common quotient
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xor dx, dx ; clear upper part
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div bx ; divide
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add dl, '0' ; convert remainder into ASCII
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push dx ; ... and store to output stack
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or ax, ax ; another iteration if value is still nonzero
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jnz .nextdigit
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; flush output stack
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mov ah, 2 ; DOS function "write character"
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.outchar:
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pop dx
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int 21h
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cmp dl, 0Ah
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jne .outchar
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ret
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; -----------------------------------------------------------------------------
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; DATA SECTION
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; score accumulators for parts 1 and 2
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part1 dw 0
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part2 dw 0
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; input filename; gets overwritten with file data later
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file: db "INPUT.TXT", 0

‎2022/03/README.md

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\--- Day 3: Rucksack Reorganization ---
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---------------------------------------
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One Elf has the important job of loading all of the [rucksacks](https://en.wikipedia.org/wiki/Rucksack) with supplies for the jungle journey. Unfortunately, that Elf didn't quite follow the packing instructions, and so a few items now need to be rearranged.
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Each rucksack has two large _compartments_. All items of a given type are meant to go into exactly one of the two compartments. The Elf that did the packing failed to follow this rule for exactly one item type per rucksack.
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## Part 1
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The Elves have made a list of all of the items currently in each rucksack (your puzzle input), but they need your help finding the errors. Every item type is identified by a single lowercase or uppercase letter (that is, `a` and `A` refer to different types of items).
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The list of items for each rucksack is given as characters all on a single line. A given rucksack always has the same number of items in each of its two compartments, so the first half of the characters represent items in the first compartment, while the second half of the characters represent items in the second compartment.
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For example, suppose you have the following list of contents from six rucksacks:
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vJrwpWtwJgWrhcsFMMfFFhFp
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jqHRNqRjqzjGDLGLrsFMfFZSrLrFZsSL
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PmmdzqPrVvPwwTWBwg
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wMqvLMZHhHMvwLHjbvcjnnSBnvTQFn
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ttgJtRGJQctTZtZT
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CrZsJsPPZsGzwwsLwLmpwMDw
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* The first rucksack contains the items `vJrwpWtwJgWrhcsFMMfFFhFp`, which means its first compartment contains the items `vJrwpWtwJgWr`, while the second compartment contains the items `hcsFMMfFFhFp`. The only item type that appears in both compartments is lowercase _`p`_.
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* The second rucksack's compartments contain `jqHRNqRjqzjGDLGL` and `rsFMfFZSrLrFZsSL`. The only item type that appears in both compartments is uppercase _`L`_.
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* The third rucksack's compartments contain `PmmdzqPrV` and `vPwwTWBwg`; the only common item type is uppercase _`P`_.
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* The fourth rucksack's compartments only share item type _`v`_.
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* The fifth rucksack's compartments only share item type _`t`_.
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* The sixth rucksack's compartments only share item type _`s`_.
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To help prioritize item rearrangement, every item type can be converted to a _priority_:
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* Lowercase item types `a` through `z` have priorities 1 through 26.
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* Uppercase item types `A` through `Z` have priorities 27 through 52.
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In the above example, the priority of the item type that appears in both compartments of each rucksack is 16 (`p`), 38 (`L`), 42 (`P`), 22 (`v`), 20 (`t`), and 19 (`s`); the sum of these is _`157`_.
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Find the item type that appears in both compartments of each rucksack. _What is the sum of the priorities of those item types?_
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Your puzzle answer was `8153`.
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## Part 2
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As you finish identifying the misplaced items, the Elves come to you with another issue.
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For safety, the Elves are divided into groups of three. Every Elf carries a badge that identifies their group. For efficiency, within each group of three Elves, the badge is the _only item type carried by all three Elves_. That is, if a group's badge is item type `B`, then all three Elves will have item type `B` somewhere in their rucksack, and at most two of the Elves will be carrying any other item type.
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The problem is that someone forgot to put this year's updated authenticity sticker on the badges. All of the badges need to be pulled out of the rucksacks so the new authenticity stickers can be attached.
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Additionally, nobody wrote down which item type corresponds to each group's badges. The only way to tell which item type is the right one is by finding the one item type that is _common between all three Elves_ in each group.
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Every set of three lines in your list corresponds to a single group, but each group can have a different badge item type. So, in the above example, the first group's rucksacks are the first three lines:
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vJrwpWtwJgWrhcsFMMfFFhFp
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jqHRNqRjqzjGDLGLrsFMfFZSrLrFZsSL
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PmmdzqPrVvPwwTWBwg
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And the second group's rucksacks are the next three lines:
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wMqvLMZHhHMvwLHjbvcjnnSBnvTQFn
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ttgJtRGJQctTZtZT
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CrZsJsPPZsGzwwsLwLmpwMDw
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In the first group, the only item type that appears in all three rucksacks is lowercase `r`; this must be their badges. In the second group, their badge item type must be `Z`.
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Priorities for these items must still be found to organize the sticker attachment efforts: here, they are 18 (`r`) for the first group and 52 (`Z`) for the second group. The sum of these is _`70`_.
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Find the item type that corresponds to the badges of each three-Elf group. _What is the sum of the priorities of those item types?_
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Your puzzle answer was `2342`.
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## Solution Notes
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Just intersections of sets, nothing special to see here.
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An x86 DOS implementation of this task is still perfectly in the realm of the possible; having to implement bitfield-based sets from scratch isn't _that_ much fun, though -- and it takes a surprisingly high amount of code space too.
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* Part 1, Python: 122 bytes, <100 ms
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* Part 2, Python: 128 bytes, <100 ms
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* Parts 1+2, x86 DOS Assembly: 306 bytes (assembled)

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