2018/day5b.sh

   1 read line < ${1-/dev/tty}
   2 echo "Starting with ${#line} characters"
   3 orig=$line
   4 best_len=${#line}
   5 for outer in {a..z}; do
   6     adj=${orig//[$outer${outer^}]/}
   7     line=$orig
   8     while [[ $line != $adj ]]; do
   9         line=$adj
  10         for l in {a..z}; do
  11             eval adj=\${adj//$l${l^}}
  12             eval adj=\${adj//${l^}$l}
  13         done
  14     done
  15     echo "Letter $outer gives ${#line} characters"
  16     if [[ ${#line} -lt $best_len ]]; then
  17         best_len=${#line}
  18         best_letter=$outer
  19     fi
  20 done
  21 echo "Best letter $best_letter gives $best_len"