advent-of-code/2024/day-4/solution-2.sh

#!/usr/bin/env bash

sed 's/^A/B/g;s/A$/B/g' input.txt | paste -s -d '' | 
  perl -lne '
    print "$1$4$2$3" 
    while 
      /(?<=(.).(.).{138})A(?=.{138}(.).(.))/g
  ' | 
  grep -Ec '(SM|MS){2}'
Day 4 2024-12-04 20:46:24 +08:00			`#!/usr/bin/env bash`

Fix missing check for A at borders 2024-12-04 23:08:09 +08:00			`sed 's/^A/B/g;s/A$/B/g' input.txt \| paste -s -d '' \|`
Day 4 2024-12-04 20:46:24 +08:00			`perl -lne '`
			`print "$1$4$2$3"`
			`while`
Update regex 2024-12-04 22:15:25 +08:00			`/(?<=(.).(.).{138})A(?=.{138}(.).(.))/g`
Day 4 2024-12-04 20:46:24 +08:00			`' \|`
Update regex 2024-12-04 22:15:25 +08:00			`grep -Ec '(SM\|MS){2}'`