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 filename="${1:-input.txt}"
  13
  14 for num in $(<"$filename"); do
  15     cur_line=$((cur_line+1))
  16     windows[$cur_window]=$num
  17     if [ $cur_window -gt 1 ]; then
  18         ((windows[$((cur_window - 1))]+=$num))
  19     fi
  20     if [ $cur_window -gt 2 ]; then
  21         ((windows[$((cur_window - 2))]+=$num))
  22     fi
  23     ((cur_window+=1))
  24
  25     case $check in
  26         0)
  27             check=1
  28             cur_number=$num
  29             prev_number=$num
  30             continue
  31             ;;
  32         1)
  33             cur_number=$num
  34             if [ $cur_number -gt $prev_number ]; then
  35                 ((count+=1))
  36             fi
  37             prev_number=$num
  38             ;;
  39     esac
  40 done
  41
  42 # remove last 2 entries for windows array
  43 unset windows[$((cur_window+1))]
  44 unset windows[$((cur_window+2))]
  45
  46 echo "$count is the answer"
  47
  48 # start from window 2, then we just compare to previous
  49 window=2
  50 count=0
  51
  52 while [ $window -le ${#windows[@]} ]; do
  53     if [ ${windows[$((window-1))]} -lt ${windows[$window]} ]; then
  54         ((count+=1))
  55     fi
  56     ((window+=1))
  57 done
  58
  59 echo "$count is the 3 value sum answer"