day01/count.sh

   1 #!/bin/bash
   2
   3 check=0
   4 cur_number=0
   5 prev_number=0
   6 count=0
   7 cur_line=0
   8 cur_window=1
   9
  10 declare -a windows
  11
  12 for num in $(<input.txt); do
  13     cur_line=$((cur_line+1))
  14     windows[$cur_window]=$num
  15     if [ $cur_window -gt 1 ]; then
  16         ((windows[$((cur_window - 1))]+=$num))
  17     fi
  18     if [ $cur_window -gt 2 ]; then
  19         ((windows[$((cur_window - 2))]+=$num))
  20     fi
  21     ((cur_window+=1))
  22
  23     case $check in
  24         0)
  25             check=1
  26             cur_number=$num
  27             prev_number=$num
  28             continue
  29             ;;
  30         1)
  31             cur_number=$num
  32             if [ $cur_number -gt $prev_number ]; then
  33                 ((count+=1))
  34             fi
  35             prev_number=$num
  36             ;;
  37     esac
  38 done
  39
  40 # remove last 2 entries for windows array
  41 unset windows[$((cur_window+1))]
  42 unset windows[$((cur_window+2))]
  43
  44 echo "$count is the answer"
  45
  46 # start from window 2, then we just compare to previous
  47 window=2
  48 count=0
  49
  50 while [ $window -le ${#windows[@]} ]; do
  51     if [ ${windows[$((window-1))]} -lt ${windows[$window]} ]; then
  52         ((count+=1))
  53     fi
  54     ((window+=1))
  55 done
  56
  57 echo "$count is the 3 value sum answer"