Advent of Code 2022 Day 9 (BaseA Style)

[AlteryxCommunityTeam]

Discussion thread for day 9 of the Advent of Code - https://adventofcode.com/2022/day/9

[mmontgomery]

So many possible mistakes with hardcoding P2. Eventually got there but had the idea right early.

Spoiler

[LiuZhang]

Spoiler

There is a lot of if's for part 1, quite a bit testing to get it right as each line all look so alike.

Part 2 turns out to be easy with an iterative macro on part 1.

[ApekshaSharma]

Spoiler

My Approach for day 9 !

 

[estherb47]

My solution to part 2 is brute force ugliness (but runs quickly). Pretty happy with my formula to determine tail position for part 1.

Spoiler

First attempt was to calculate the X and Y coordinates of the tail in separate steps. That didn't work with my logic. So here is the not-so-ugly formula for the Multirow -

IF IsEmpty([Row-1:Field1]) THEN [Position_T] ELSEIF Abs([X_H]-tonumber(left([Row-1:Position_T],findstring([Row-1:Position_T],","))))<=1 AND
ABS([Y_H]-tonumber(right([Row-1:Position_T],findstring(reversestring([Row-1:Position_T]),","))))<=1 THEN
[Row-1:Position_T]
ELSE tostring([Row-1:X_H])+","+tostring([Row-1:Y_H])
ENDIF

[grossal]

Now that I've gotten over my trauma and shock over my horrible solution, I'd like to add this one as well.

Spoiler

Macro part 1:

As it followed the wrong approach... I had to do something different for part 2 ... and it's a mess.

[SeanAdams]

This was not an easy one - made even tougher by the fact that I didn't read the original instructions in part 1 properly but the issue was obscured until I started to move stuff round in part 2.

Spoiler

This solution has several parts:

Part 1: clean up the moves to only work in 1 step moves:

This just takes multiple step moves, and turns them into a series of one-step moves

Part 2: Do the magic bit and count the results

The magic bit: Part 1:
This is an iterative macro - which iterates over the moves, and uses a YXDB to also pass the position to each new iteration

Within this there are 2 sub-macros:
Move the Header node:    
The logic of moving the header is different than moving the tailing nodes - so it's split into two different macros.

Move Header:

And then moving the tailing nodes is also an iterative macro:

The magic part is the move formula for the trailing item:

That was a long couple of days :-) 

[Yoshiro_Fujimori]

I know this is ugly, but at least it passed.

Spoiler

Main

Macro

Formula in the macro:

IF IsEmpty([Row-1:tail_xy]) THEN "0,0" // 初期値

// headがtailと隣接 -> 動かない
ELSEIF
  ABS(  ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$1"))
      - ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) ) <= 1
  AND  
  ABS(  ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$2"))
      - ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) ) <= 1
THEN [Row-1:tail_xy]

// headがtailの上方 -> 上へ1
ELSEIF REGEX_Replace([head_xy], "(.+),(.+)", "$1")
     = REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")
  AND  ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$2"))
     > ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) + 1
THEN
  REGEX_Replace([head_xy], "(.+),(.+)", "$1")
  + ","
  + ToString(ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) + 1) 

// headがtailの下方 -> 下へ1
ELSEIF REGEX_Replace([head_xy], "(.+),(.+)", "$1")
     = REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")
  AND  ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$2"))
     < ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) - 1
THEN
  REGEX_Replace([head_xy], "(.+),(.+)", "$1")
  + ","
  + ToString(ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) - 1) 

// headがtailの右方 -> 右へ1
ELSEIF REGEX_Replace([head_xy], "(.+),(.+)", "$2")
     = REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")
  AND  ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$1"))
     > ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) + 1
THEN
  ToString(ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) + 1)
  + "," 
  + REGEX_Replace([head_xy], "(.+),(.+)", "$2")

// headがtailの左方 -> 左へ1
ELSEIF REGEX_Replace([head_xy], "(.+),(.+)", "$2")
     = REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")
  AND  ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$1"))
     < ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) - 1
THEN
  ToString(ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) - 1)
  + "," 
  + REGEX_Replace([head_xy], "(.+),(.+)", "$2")

// headがtailの右上 -> 右上へ1
ELSEIF
    ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$1"))
  - ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) >= 1
  AND
    ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$2"))
  - ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) >= 1
THEN
  ToString(ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) + 1)
  + "," +
  ToString(ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) + 1)

// headがtailの右下 -> 右下へ1
ELSEIF
    ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$1"))
  - ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) >= 1
  AND
    ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$2"))
  - ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) <= -1
THEN
  ToString(ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) + 1)
  + "," +
  ToString(ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) - 1)

// headがtailの左上 -> 左上へ1
ELSEIF
    ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$1"))
  - ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) <= -1
  AND
    ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$2"))
  - ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) >= 1
THEN
  ToString(ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) - 1)
  + "," +
  ToString(ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) + 1)

// headがtailの左下 -> 左下へ1
ELSEIF
    ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$1"))
  - ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) <= -1
  AND
    ToNumber(REGEX_Replace([head_xy], "(.+),(.+)", "$2"))
  - ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) <= -1
THEN
  ToString(ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$1")) - 1)
  + "," +
  ToString(ToNumber(REGEX_Replace([Row-1:tail_xy], "(.+),(.+)", "$2")) - 1)

ELSE [Row-1:tail_xy]
ENDIF

[DaisukeTsuchiya]

Spoiler

[DataNath]

Finally got time to catch up on a couple of days and finished off 9!

Spoiler

Iterative macro - turns each knot into the new head:

[JoshuaB]

Can you share this excel file? Really great example @grossal !