day3/count_trees.sh

   1 #!/bin/bash
   2
   3 start_letter=0
   4 line_number=0
   5 tree_count=0
   6
   7 for line in $(<input.txt); do
   8     line_number=$((line_number+1))
   9     if [ $line_number -eq 1 ]; then
  10         continue
  11     fi
  12     start_letter=$((start_letter+3))
  13     if [ $start_letter -ge ${#line} ]; then
  14         start_letter=$((start_letter - ${#line}))
  15     fi
  16     if [ "${line:$start_letter:1}" = "#" ]; then
  17         tree_count=$((tree_count+1))
  18     fi
  19 done
  20
  21 echo "Hit $tree_count trees"
  22
  23 exit 0
  24
  25 #!/usr/bin/python3
  26
  27 trees_count = 0
  28 position = 3 # forth square in, we moved 3 right from where we were, 0 + 3 -> 3
  29 on_first_line = True
  30 line_number = 0
  31
  32 for line in open("input.txt", "r"):
  33     line_number += 1
  34     print("line: ", line_number)
  35     line = line.rstrip()
  36     print(line)
  37     if on_first_line:
  38         on_first_line = False
  39         continue
  40     print(line[position], position)
  41     if line[position] == "#":
  42         trees_count += 1
  43         print("hit tree")
  44     else:
  45         print("missed tree")
  46     # now add 3 to the position
  47     position += 3
  48     if position >= len(line):
  49         position = position - len(line)
  50
  51 print("There were", trees_count, "trees")