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advent-of-code/2022/day03/aoc.bash

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#!/usr/bin/env bash
#
# aoc.bash: Advent of Code 2022, day 2
#
# Copyright (C) 2022 Bruno Raoult ("br")
# Licensed under the GNU General Public License v3.0 or later.
# Some rights reserved. See COPYING.
#
# You should have received a copy of the GNU General Public License along with this
# program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
#
# SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
. common.bash
export LANG=C
declare -a tot=(1 2)
declare -a input
# get priority value for an item
# $1: character
prio() {
local -n _val="$1"
local _char="$2"
printf -v _val "%d" "'$_char"
if [[ $_char > "Z" ]]; then # a-z
((_val += (1 - 97) ))
else # A-Z
((_val += (27 - 65) ))
fi
}
parse() {
readarray -t input
}
part1() {
local line half1 half2 result=""
local -i len half i prio
res=0
for line in "${input[@]}"; do
echo "$line"
(( len = ${#line}, half = len/2 ))
half1="${line:0:half}"
half2="${line:half}"
result=""
printf "[%d] l=%d h=%d [%s / %s]\n" "$num" "$len" "$half" "$half1" "$half2"
#c="${half1//[^${half2}]}"
#prio prio "${c:0:1}"
#(( part1 += prio ))
for (( i = 0; i < half; ++i )); do
c=${half1:$i:1}
if [[ $result != *$c* && $half2 == *$c* ]]; then
echo "found $c"
result=$result$c
prio prio "${c:0:1}"
(( res += prio ))
#printf "%d prio(%c)=%d tot=%d\n" "$line" "$c" "$prio" "$part1"
fi
done
done
}
part2() {
local common one two three
local -i len half i prio
res=0
for (( i = ${#input[@]} - 1; i > 1; i -= 3)); do
three=${input[i]}
two=${input[i - 1]}
one=${input[i - 2]}
common=${three//[^${two}]}
common=${common//[^${one}]}
#common=${}
#echo "$line"
#(( len = ${#line}, half = len/2 ))
#half1="${line:0:half}"
#half2="${line:half}"
#result=""
printf "[%d] 1=%s 2=%s 3=%s c=%s\n" "$i" "$one" "$two" "$three" "$common"
#c="${half1//[^${half2}]}"
prio prio "${common:0:1}"
(( res += prio ))
done
}
solve() {
if (($1 == 1)); then
part1
else
part2
fi
#res="${tot[$1]}"
}
main "$@"
exit 0