#! /bin/bash

#set -x

FILE_IN="${1}"

left_list=()
right_list=()

while read -r l; do
  echo "reading new line [$l]"
  IFS=" "
  read -ra line_split <<< "${l}"
  unset IFS
  echo "first number [${line_split[0]}]"
  echo "second number [${line_split[1]}]"
  left_list+=("${line_split[0]}")
  right_list+=("${line_split[1]}")
done <"$FILE_IN"

echo "${left_list[@]}"
echo "${right_list[@]}"

if [[ ${#left_list[@]} -ne ${#right_list[@]} ]]; then
  echo "arrays dont match, wtf?"
  exit 1
else
  echo "length of lists ${#left_list[@]}"
fi

list_similarity=()

for i in "${left_list[@]}"; do
  echo "checking for ${i}"
  IFS=$'\n'
  count="$(grep -oc "${i}" <<<"${right_list[*]}")"
  unset IFS
  list_similarity+=($((i*count)))
done

final_out=0

for v in "${list_similarity[@]}"; do
  final_out=$((final_out + v))
done

echo "final output: ${final_out}"