Discussion on: AoC Day 1: Chronal Calibration

I wanted to solve these ones in bash, which I've been focussing on learning lately. First challenge was great, found a simple oneliner:

echo $(( 0$(tr -d '\n' < ./day1/input.txt) ))

But part 2 was a nightmare. Super slow. Ended up using JS in the end, but would still love to know anyone's thoughts on how this could be optimised. Wasn't watching the clock but think it took >20 mins to run!

It's collecting previously computed frequencies in an array, and checking for the frequency in the array each time a new frequency is computed. Is it the maths that's likely to be so slow, or the looping, or both?

declare -i total=0
seen=()
found=

array_contains () {
  for i in "${seen[@]}"; do
    if [[ "$i" == "$1" ]]; then
      return 0
    fi
  done
  return 1
}

while [[ ! $found ]]; do
  for line in $(cat $1); do
    total=$(( ${total}${line} ))

    if array_contains "$total"; then
      echo "FOUND " $total
      found=1
      break
    else
      echo 'not found'
    fi

    seen+=($total)
  done
done

# ./main.sh input.txt