2022/day02.m4

   1 divert(-1)dnl -*- m4 -*-
   2 # Usage: m4 [-Dfile=day02.input] day02.m4
   3
   4 include(`common.m4')ifelse(common(02), `ok', `',
   5 `errprint(`Missing common initialization
   6 ')m4exit(1)')
   7
   8 define(`part1', 0)define(`part2', 0)
   9 define(`do', `define(`part1', eval(part1`+($2+$1)%3*3+$1'))define(`part2',
  10 eval(part2`+$1*3-($3-$1)%3'))')
  11 define(`setup', `define(`$1', `do('$`1, $2, $3)')')
  12 translit(include(defn(`file')), `XYZ 'nl, `123()'setup(`A', 0, 4)setup(`B',
  13 2, 3)setup(`C', 1, 5))
  14
  15 ifelse(`dnl golfing variants, the newline after Y is essential
  16 dnl part1
  17 eval(translit(include(f),X Y
  18 Z,1(2)3define(d,`define($1,+($2+$`1')%3*3+$`1')')d(A,0)d(B,2)d(C,1)))
  19 dnl part2
  20 eval(translit(include(f),X Y
  21 Z,1(2)3define(d,`define($1,+$`1'*3-($2-$`1')%3)')d(A,4)d(B,3)d(C,5)))
  22 ')
  23
  24 divert`'part1
  25 part2