aoc2023/day1/day1.sh

#!/bin/bash

replacedigits() {
	rep="$1"
	i="0"
	len="${#rep}"
	ret=""
	while [ $i -lt ${len} ]; do
		case "${rep:${i}:1}" in
			0|1|2|3|4|5|6|7|8|9)
				ret="${ret}${rep:${i}:1}"
				i=$((i+1))
				continue
				;;
		esac
		#echo ${i} ${rep} ${rep:${i}:1}
		#echo ${rep:${i}:3} ${rep:${i}:4} ${rep:${i}:5} 
		if [ ${rep:${i}:3} = one ]; then
			ret="${ret}1"
		elif [ ${rep:${i}:3} = two ]; then
			ret="${ret}2"
		elif [ ${rep:${i}:5} = three ]; then
			ret="${ret}3"
		elif [ ${rep:${i}:4} = four ]; then
			ret="${ret}4"
		elif [ ${rep:${i}:4} = five ]; then
			ret="${ret}5"
		elif [ ${rep:${i}:3} = six ]; then
			ret="${ret}6"
		elif [ ${rep:${i}:5} = seven ]; then
			ret="${ret}7"
		elif [ ${rep:${i}:5} = eight ]; then
			ret="${ret}8"
		elif [ ${rep:${i}:4} = nine ]; then
			ret="${ret}9"
		fi
		i="$((i+1))"
	done
	echo "$ret"
}

sum=0;
for number in $(cat "$1" | sed s/[^0-9]//g); do
	sum=$((sum+${number:0:1}*10+${number:${#number}-1:${#number}}))
done
printf "part 1: %d\n" $sum

sum=0
for number in $(cat "$1" | sed s/one/o1e/g | sed s/two/t2o/g | sed s/three/t3hee/g | sed s/four/f4ur/g | sed s/five/f5ve/g | sed s/six/s6x/g | sed s/seven/s7ven/g | sed s/eight/e8ght/g | sed s/nine/n9ne/g | sed s/[^0-9]//g); do
	sum=$((sum+${number:0:1}*10+${number:${#number}-1:${#number}}))
done
printf "part 2 (faster alt): %d\n" $sum

sum=0;
for line in $(cat "$1"); do
	number="$(replacedigits $line)"
	digits="$((10*${number:0:1}+${number:$((${#number}-1)):${#number}}))"
	#printf "%s %s %s\n" $line $number $digits
	sum=$((sum+${digits}))
done
printf "part 2: %d\n" $sum