AoC 2025 Day 11 - bash

Author: pareronia

README.md

@@ -10,7 +10,7 @@
 | ---| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
 | python3 | [✓](src/main/python/AoC2025_01.py) | [✓](src/main/python/AoC2025_02.py) | [✓](src/main/python/AoC2025_03.py) | [✓](src/main/python/AoC2025_04.py) | [✓](src/main/python/AoC2025_05.py) | [✓](src/main/python/AoC2025_06.py) | [✓](src/main/python/AoC2025_07.py) | [✓](src/main/python/AoC2025_08.py) | [✓](src/main/python/AoC2025_09.py) | [✓](src/main/python/AoC2025_10.py) | [✓](src/main/python/AoC2025_11.py) |  |
 | java | [✓](src/main/java/AoC2025_01.java) | [✓](src/main/java/AoC2025_02.java) | [✓](src/main/java/AoC2025_03.java) | [✓](src/main/java/AoC2025_04.java) | [✓](src/main/java/AoC2025_05.java) | [✓](src/main/java/AoC2025_06.java) | [✓](src/main/java/AoC2025_07.java) | [✓](src/main/java/AoC2025_08.java) | [✓](src/main/java/AoC2025_09.java) | [✓](src/main/java/AoC2025_10.java) | [✓](src/main/java/AoC2025_11.java) |  |
-| bash | [✓](src/main/bash/AoC2025_01.sh) | [✓](src/main/bash/AoC2025_02.sh) | [✓](src/main/bash/AoC2025_03.sh) | [✓](src/main/bash/AoC2025_04.sh) | [✓](src/main/bash/AoC2025_05.sh) | [✓](src/main/bash/AoC2025_06.sh) | [✓](src/main/bash/AoC2025_07.sh) |  |  |  |  |  |
+| bash | [✓](src/main/bash/AoC2025_01.sh) | [✓](src/main/bash/AoC2025_02.sh) | [✓](src/main/bash/AoC2025_03.sh) | [✓](src/main/bash/AoC2025_04.sh) | [✓](src/main/bash/AoC2025_05.sh) | [✓](src/main/bash/AoC2025_06.sh) | [✓](src/main/bash/AoC2025_07.sh) |  |  |  | [✓](src/main/bash/AoC2025_11.sh) |  |
 <!-- @END:ImplementationsTable:2025@ -->
 
 ## 2024

src/main/bash/AoC2025_11.sh

@@ -0,0 +1,104 @@
+#!/bin/bash
+#
+# Advent of Code 2025 Day 11
+#
+
+year=2025
+day=11
+
+declare -A edges
+declare -A cache
+
+create_graph() {
+    while read -r line || [ -n "$line" ]; do
+        local node="${line%%:*}"
+        local neighbours="${line:${#node}+2}"
+        edges[$node]="$neighbours"
+    done < "$1"
+    return 0
+}
+
+dfs() {
+    local node="$1"
+    [[ -n "${cache[$node]}" ]] && {
+        return 0
+    }
+    [ "$node" = "$end" ] && {
+        ((cache["$node"] += 1))
+        return 0
+    }
+    IFS=' ' read -ra neighbours <<< "${edges[$node]}"
+    local n
+    for n in "${neighbours[@]}"; do
+        dfs "$n"
+        ((cache["$node"] += cache["$n"]))
+    done
+    return 0
+}
+
+count_all_paths() {
+    cache=()
+    local start="$1"
+    local end="$2"
+    dfs "$start"
+    echo "${cache[$start]}"
+    return 0
+}
+
+part1() {
+    create_graph "$1"
+    count_all_paths "you" "out"
+    return 0
+}
+
+part2() {
+    create_graph "$1"
+    local -i ans1=1
+    ((ans1 *= $(count_all_paths "svr" "dac")))
+    ((ans1 *= $(count_all_paths "dac" "fft")))
+    ((ans1 *= $(count_all_paths "fft" "out")))
+    local -i ans2=1
+    ((ans2 *= $(count_all_paths "svr" "fft")))
+    ((ans2 *= $(count_all_paths "fft" "dac")))
+    ((ans2 *= $(count_all_paths "dac" "out")))
+    echo $((ans1 + ans2))
+    return 0
+}
+
+tests() {
+    # shellcheck disable=SC2034
+    {
+        sample1=(
+            "aaa: you hhh"
+            "you: bbb ccc"
+            "bbb: ddd eee"
+            "ccc: ddd eee fff"
+            "ddd: ggg"
+            "eee: out"
+            "fff: out"
+            "ggg: out"
+            "hhh: ccc fff iii"
+            "iii: out"
+        )
+        sample2=(
+            "svr: aaa bbb"
+            "aaa: fft"
+            "fft: ccc"
+            "bbb: tty"
+            "tty: ccc"
+            "ccc: ddd eee"
+            "ddd: hub"
+            "hub: fff"
+            "eee: dac"
+            "dac: fff"
+            "fff: ggg hhh"
+            "ggg: out"
+            "hhh: out"
+        )
+    }
+
+    TEST part1 sample1 5
+    TEST part2 sample2 2
+}
+
+source "$(dirname "$0")/aoc_main.sh"