day3/count_trees_2.sh

   1 #!/bin/bash
   2
   3 moves=("1,1" "3,1" "5,1" "7,1" "1,2")
   4
   5 count_trees() {
   6     right=$1
   7     down=$2
   8     cur_down=-1 # we want to skip the very first line
   9     pos=0
  10     tree_count=0
  11     for line in $(<input.txt); do
  12         cur_down=$((cur_down+1))
  13         if [ $cur_down -eq $down ]; then
  14             cur_down=0
  15             pos=$((pos + $right))
  16             if [ $pos -ge ${#line} ]; then
  17                 pos=$((pos - ${#line}))
  18             fi
  19             if [ ${line:$pos:1} = "#" ]; then
  20                 tree_count=$((tree_count+1))
  21             fi
  22         fi
  23     done
  24     echo "$tree_count"
  25 }
  26
  27 mult_total=1
  28 for move in ${moves[@]}; do
  29     down=${move#*,}
  30     right=${move%,*}
  31     trees=$(count_trees $right $down)
  32     echo "Move: $move has $trees trees"
  33     mult_total=$((mult_total * $trees))
  34 done
  35
  36 echo "Answer: $mult_total"
  37
  38 exit 0
  39
  40 #!/usr/bin/python3
  41
  42 trees_count = []
  43 on_first_line = True
  44 line_number = 0
  45
  46 move_types = ((1,1), (3,1), (5,1), (7,1), (1,2))
  47
  48 for move in move_types:
  49     line_offset = 0
  50     tree_count = 0
  51     position = move[0]
  52     first_line = True
  53     for line in open("input.txt", "r"):
  54         line = line.rstrip()
  55         print(move[1], line_offset)
  56         if line_offset < move[1] or first_line:
  57             line_offset += 1
  58             if line_offset >= move[1]:
  59                 first_line = False
  60             continue
  61         line_offset = 1
  62         if line[position] == "#":
  63             tree_count += 1
  64         position += move[0]
  65         if position >= len(line):
  66             position = position - len(line)
  67     trees_count.append(tree_count)
  68     tree_count = 0
  69
  70 mult_result = 1
  71 for x in trees_count:
  72     print(x)
  73     mult_result *= x
  74
  75 print("There were", mult_result, "trees")