day6/get_yes_counts_2.sh

   1 #!/bin/bash
   2
   3 set -u
   4 set -e
   5
   6 declare -a group_questions
   7
   8 parse_file() {
   9     exec 3<input.txt
  10     declare -A questions
  11     people_in_group=0
  12     while read -u 3 line; do
  13         #remove new lines
  14         line=${line//$'\r'//}
  15         line=${line//$'\n'//}
  16         if [ "$line" == "" ]; then
  17             question_string=""
  18             for key in "${!questions[@]}"; do
  19                 if [ $people_in_group -eq ${questions[$key]} ]; then
  20                     question_string+="${key}"
  21                 fi
  22             done
  23             group_questions+=($question_string)
  24             unset questions
  25             declare -A questions
  26             people_in_group=0
  27             continue
  28         fi
  29         people_in_group=$((people_in_group+1))
  30         # go through each character of line
  31         for (( a=0; a<${#line}; a++ )); do
  32             question=${line:$a:1}
  33             if [ ${questions["$question"]+a} ]; then
  34                 questions["$question"]=$((${questions["$question"]}+1))
  35             else
  36                 questions["$question"]=1
  37             fi
  38         done
  39     done
  40
  41     # last line was hit, so we need to process that too
  42     question_string=""
  43     for key in "${!questions[@]}"; do
  44         if [ $people_in_group -eq ${questions[$key]} ]; then
  45             question_string+="${key}"
  46         fi
  47     done
  48     group_questions+=($question_string)
  49     unset questions
  50 }
  51
  52 parse_file
  53
  54 sum_of_groups=0
  55 for group in "${group_questions[@]}"; do
  56     sum_of_groups=$((sum_of_groups+${#group}))
  57 done
  58
  59 echo "Sum of groups: $sum_of_groups"