day01/get_fuel_required.sh

   1 #!/bin/bash
   2
   3 filename=${1:-input.txt}
   4
   5 exec 3<"$filename"
   6
   7 fuel_total=0
   8 fuel_and_extra=0
   9 while read -u 3 mass; do
  10     fuel=$((($mass / 3) - 2))
  11     fuel_total=$((fuel_total+$fuel))
  12     fuel_and_extra=$((fuel_and_extra+$fuel))
  13     extra_fuel=$((($fuel / 3) - 2))
  14     while [ $extra_fuel -gt 0 ]; do
  15         fuel_and_extra=$((fuel_and_extra+$extra_fuel))
  16         extra_fuel=$((($extra_fuel / 3) - 2))
  17     done
  18 done
  19
  20 echo $fuel_total
  21 echo $fuel_and_extra