day06 part01 & day07

day06.sh

@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+unset PATH
+readonly PATH
+source ./utils/main.sh
+
+coord_to_index() {
+  local width="$1" x="$2" y="$3"
+  printf '%d' "$((y * width + x))"
+}
+
+index_to_coord() {
+  local width="$1" index="$2"
+  printf '%d %d\n' "$((index % width))" "$((index / width))"
+}
+
+p1() {
+  local input="$1" width=0 height=0
+  local line arr=() x y dir='u'
+  local -A visited
+
+  while read -r line; do
+    ((height++))
+    [[ "$width" ]] && width="${#line}"
+    while IFS= read -rd '' -n 1 char; do
+      [[ "$char" == $'\n' ]] && continue
+      arr+=("$char")
+    done <<<"$line"
+  done <<<"$input"
+
+  local i
+  for i in "${!arr[@]}"; do
+    [[ "${arr[i]}" == '^' ]] && {
+      read -r x y <<<"$(index_to_coord "$width" "$i")"
+      arr[i]="."
+      visited=(["$x $y"]=1)
+      break
+    }
+  done
+
+  while :; do
+    case "$dir" in
+      u)
+        ((y - 1 < 0)) && break
+        [[ "${arr["$(coord_to_index "$width" "$x" "$((y - 1))")"]}" == '#' ]] && dir='r' && continue
+        ((y--))
+        ;;
+      r)
+        ((x + 1 >= width)) && break
+        [[ "${arr["$(coord_to_index "$width" "$((x + 1))" "$y")"]}" == '#' ]] && dir='d' && continue
+        ((x++))
+        ;;
+      d)
+        ((y + 1 >= height)) && break
+        [[ "${arr["$(coord_to_index "$width" "$x" "$((y + 1))")"]}" == '#' ]] && dir='l' && continue
+        ((y++))
+        ;;
+      l)
+        ((x - 1 < 0)) && break
+        [[ "${arr["$(coord_to_index "$width" "$((x - 1))" "$y")"]}" == '#' ]] && dir='u' && continue
+        ((x--))
+        ;;
+      *) : ;;
+    esac
+    visited+=(["$x $y"]=1)
+  done
+
+  printf '%s' "${#visited[@]}"
+}
+
+main "$@"

day07.sh

@@ -0,0 +1,65 @@
+#!/usr/bin/env bash
+unset PATH
+readonly PATH
+source ./utils/main.sh
+source ./utils/array.sh
+NUM_JOBS="\j"
+
+solve() {
+  local part="$1" target="$2" curr="$3" rest=("${@:4}")
+
+  ((${#rest[@]} == 0)) && {
+    ((curr == target)) && echo "$target" && return 0
+    return 1
+  }
+
+  solve "$part" "$target" "$((curr + rest[0]))" "${rest[@]:1}" ||
+    solve "$part" "$target" "$((curr * rest[0]))" "${rest[@]:1}" || {
+    ((part == 1)) && return 1
+    solve "$part" "$target" "${curr}${rest[0]}" "${rest[@]:1}"
+  }
+}
+
+p1() {
+  local input="$1" result=0
+
+  while read -r num; do
+    ((result += num))
+  done < <(
+    while read -r line; do
+      while ((${NUM_JOBS@P} >= 16)); do wait -n; done
+      {
+        local nums=() target
+        read -ra nums <<<"${line#*: }"
+        target="${line%:*}"
+        solve 1 "$target" "${nums[@]}"
+      } &
+    done <<<"$input"
+    wait
+  )
+
+  printf '%d' "$result"
+}
+
+p2() {
+  local input="$1" result=0
+
+  while read -r num; do
+    ((result += num))
+  done < <(
+    while read -r line; do
+      while ((${NUM_JOBS@P} >= 16)); do wait -n; done
+      {
+        local nums=() target
+        read -ra nums <<<"${line#*: }"
+        target="${line%:*}"
+        solve 2 "$target" "${nums[@]}"
+      } &
+    done <<<"$input"
+    wait
+  )
+
+  printf '%d' "$result"
+}
+
+main "$@"