2015/advent11.sh

   1 valid() {
   2     case $1 in
   3         *[iol]*) return 1;;
   4         *abc*|*bcd*|*cde*|*def*|*efg*|*fgh*|*pqr*|*qrs*|*rst*\
   5             |*stu*|*tuv*|*uvw*|*vwx*|*wxy*|*xyz*) ;;
   6         *) return 1;;
   7     esac
   8     first=$(echo $1 | sed '/\(.\)\1/{s/.*\(.\)\1.*/\1/;q}; Q1') || return 1
   9     echo $1 | sed -n "/\([^$first]\)\1/q; q1"
  10 }
  11 next() {
  12     case $1 in
  13         *i?*) next=${1%i*}j
  14               next+=${a:${#next}}
  15               return;;
  16         *l?*) next=${1%l*}m
  17               next+=${a:${#next}}
  18               return;;
  19         *o?*) next=${1%o*}p
  20               next+=${a:${#next}}
  21               return;;
  22     esac
  23     next=$(echo $1 | sed 's/z$/0/; s/y$/z/; s/x$/y/; s/w$/x/; s/v$/w/;
  24                           s/u$/v/; s/t$/u/; s/s$/t/; s/r$/s/; s/q$/r/;
  25                           s/p$/q/; s/[no]$/p/; s/m$/n/; s/[kl]$/m/;
  26                           s/j$/k/; s/[hi]$/j/; s/g$/h/; s/f$/g/; s/e$/f/;
  27                           s/d$/e/; s/c$/d/; s/b$/c/; s/a$/b/; s/0/0a/')
  28     while case $next in *0*) : ;; *) false ;; esac; do
  29         next=$(echo $next | sed 's/z0/1/; s/y0/z/; s/x0/y/; s/w0/x/; s/v0/w/;
  30                                  s/u0/v/; s/t0/u/; s/s0/t/; s/r0/s/; s/q0/r/;
  31                                  s/p0/q/; s/n0/p/; s/m0/n/; s/k0/m/;
  32                                  s/j0/k/; s/h0/j/; s/g0/h/; s/f0/g/; s/e0/f/;
  33                                  s/d0/e/; s/c0/d/; s/b0/c/; s/a0/b/; s/1/0a/')
  34     done
  35 }
  36 for arg; do
  37     a=$(printf '%0*d' ${#arg} 0 | tr 0 a)
  38     tries=0
  39     echo "searching for password after $arg"
  40     while ! valid $arg; do
  41         tries=$((tries+1))
  42         next $arg
  43         arg=$next
  44         (( $tries % 1000 )) || echo "trying $next"
  45     done
  46     echo "found $next after $tries tries"
  47 done