commit de750de96a80fbd7507f07890a76eca66cd9a7b4
Author: Hubert Van De Walle <hubv@protonmail.com>
Date:   Tue Dec 1 02:12:55 2020 +0100

    Initial commit

diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..0af84ce
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,17 @@
+# editorconfig.org
+root = true
+
+[*]
+indent_style = space
+indent_size = 4
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.{kt, kts}]
+indent_size = 4
+insert_final_newline = true
+max_line_length = 120
+disabled_rules = no-wildcard-imports
+kotlin_imports_layout = idea
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..3ccfdec
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+.gradle
+.session
+build/
+.idea/
diff --git a/.sdkmanrc b/.sdkmanrc
new file mode 100644
index 0000000..f7480af
--- /dev/null
+++ b/.sdkmanrc
@@ -0,0 +1,5 @@
+# Enable auto-env through the sdkman_auto_env config
+# Add key=value pairs of SDKs to use below
+java=15-open
+gradle=6.8-rc-1
+kotlin=1.4.20
diff --git a/build.gradle.kts b/build.gradle.kts
new file mode 100644
index 0000000..314388d
--- /dev/null
+++ b/build.gradle.kts
@@ -0,0 +1,8 @@
+plugins {
+    id("advent-of-code")
+}
+
+adventOfCode {
+    year = 2020
+    session = file(".session").readText().trim()
+}
diff --git a/build.gradle.properties b/build.gradle.properties
new file mode 100644
index 0000000..aec0a55
--- /dev/null
+++ b/build.gradle.properties
@@ -0,0 +1,2 @@
+org.gradle.caching=true
+org.gradle.parallel=true
diff --git a/buildSrc/build.gradle.kts b/buildSrc/build.gradle.kts
new file mode 100644
index 0000000..5ad0bcc
--- /dev/null
+++ b/buildSrc/build.gradle.kts
@@ -0,0 +1,17 @@
+plugins {
+    `kotlin-dsl`
+}
+
+kotlinDslPluginOptions {
+    experimentalWarning.set(false)
+}
+
+repositories {
+    gradlePluginPortal()
+    maven { setUrl("https://kotlin.bintray.com/kotlinx") }
+}
+
+dependencies {
+    implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:1.4.20")
+    implementation("com.konghq:unirest-java:3.11.04")
+}
diff --git a/buildSrc/src/main/kotlin/AdventOfCodePlugin.kt b/buildSrc/src/main/kotlin/AdventOfCodePlugin.kt
new file mode 100644
index 0000000..f1b1816
--- /dev/null
+++ b/buildSrc/src/main/kotlin/AdventOfCodePlugin.kt
@@ -0,0 +1,56 @@
+import kong.unirest.Unirest
+import org.gradle.api.GradleException
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.tasks.SourceSetContainer
+import org.gradle.kotlin.dsl.create
+import org.gradle.kotlin.dsl.getByType
+import java.io.File
+import java.time.LocalDateTime
+
+open class AdventOfCodeExtension {
+    var session: String? = null
+    var year: Int = 2020
+}
+
+class AdventOfCodePlugin : Plugin<Project> {
+    override fun apply(project: Project) {
+        project.tasks.create("aoc") {
+            group = "Advent of Code"
+            description = "Download the input of the day"
+
+            val extension = project.extensions.create<AdventOfCodeExtension>("adventOfCode")
+
+            doLast {
+                if (extension.session == null) {
+                    throw GradleException("advent of code session not set")
+                }
+
+                val resourceDir: File = project
+                    .project(":days")
+                    .extensions
+                    .getByType<SourceSetContainer>()
+                    .getByName("main")
+                    .resources
+                    .srcDirs
+                    .first()
+
+                val currentDay = LocalDateTime.now().dayOfMonth.toString()
+                val outFile = File(resourceDir, "day" + currentDay.padStart(length = 2, padChar = '0') + ".txt")
+                val url = "https://adventofcode.com/${extension.year}/day/$currentDay/input"
+
+                Unirest.get(url)
+                    .cookie("session", extension.session)
+                    .header("Accept", "text/plain")
+                    .asString()
+                    .ifFailure {
+                        throw GradleException("Failed to get input, got status ${it.status}")
+                    }
+                    .ifSuccess {
+                        outFile.writeText(it.body)
+                        println("Saved input for day $currentDay")
+                    }
+            }
+        }
+    }
+}
diff --git a/buildSrc/src/main/kotlin/Libs.kt b/buildSrc/src/main/kotlin/Libs.kt
new file mode 100644
index 0000000..df010a2
--- /dev/null
+++ b/buildSrc/src/main/kotlin/Libs.kt
@@ -0,0 +1,27 @@
+@file:Suppress("SpellCheckingInspection")
+
+object Libs {
+
+    object Arrow {
+        const val version = "0.11.0"
+        const val core = "io.arrow-kt:arrow-core:$version"
+        const val optics = "io.arrow-kt:arrow-optics:$version"
+        const val fx = "io.arrow-kt:arrow-fx:$version"
+    }
+
+    object EclipseCollection {
+        const val api = "org.eclipse.collections:eclipse-collections-api:10.4.0"
+        const val core = "org.eclipse.collections:eclipse-collections:10.4.0"
+    }
+
+    object Jmh {
+        const val core = "org.openjdk.jmh:jmh-core:1.26"
+        const val processor = "org.openjdk.jmh:jmh-generator-annprocess:1.26"
+    }
+
+    object Tests {
+        const val assertJ = "org.assertj:assertj-core:3.18.1"
+        const val junit = "org.junit.jupiter:junit-jupiter:5.7.0"
+    }
+
+}
diff --git a/buildSrc/src/main/kotlin/java-convention.gradle.kts b/buildSrc/src/main/kotlin/java-convention.gradle.kts
new file mode 100644
index 0000000..c2ebb15
--- /dev/null
+++ b/buildSrc/src/main/kotlin/java-convention.gradle.kts
@@ -0,0 +1,23 @@
+plugins {
+    id("java-library")
+    id("junit-convention")
+}
+
+repositories {
+    mavenCentral()
+    jcenter()
+    maven { url = uri("https://dl.bintray.com/arrow-kt/arrow-kt/") }
+    maven { url = uri("https://kotlin.bintray.com/kotlinx") }
+}
+
+group = "be.vandewalleh"
+version = "1.0-SNAPSHOT"
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_15
+    targetCompatibility = JavaVersion.VERSION_15
+}
+
+tasks.withType<JavaCompile> {
+    options.encoding = "UTF-8"
+}
diff --git a/buildSrc/src/main/kotlin/junit-convention.gradle.kts b/buildSrc/src/main/kotlin/junit-convention.gradle.kts
new file mode 100644
index 0000000..08c6fb5
--- /dev/null
+++ b/buildSrc/src/main/kotlin/junit-convention.gradle.kts
@@ -0,0 +1,12 @@
+plugins {
+    java apply false
+}
+
+tasks.withType<Test> {
+    useJUnitPlatform()
+}
+
+dependencies {
+    testImplementation(Libs.Tests.junit)
+    testImplementation(Libs.Tests.assertJ)
+}
diff --git a/buildSrc/src/main/kotlin/kotlin-convention.gradle.kts b/buildSrc/src/main/kotlin/kotlin-convention.gradle.kts
new file mode 100644
index 0000000..6af74db
--- /dev/null
+++ b/buildSrc/src/main/kotlin/kotlin-convention.gradle.kts
@@ -0,0 +1,25 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
+plugins {
+    id("java-convention")
+    kotlin("jvm")
+}
+
+dependencies {
+    implementation(kotlin("stdlib-jdk8"))
+    implementation(platform("org.jetbrains.kotlin:kotlin-bom:1.4.20"))
+}
+
+tasks.withType<KotlinCompile> {
+    kotlinOptions {
+        jvmTarget = "15"
+        javaParameters = true
+        freeCompilerArgs = listOf(
+            "-Xinline-classes",
+            "-Xno-param-assertions",
+            "-Xno-call-assertions",
+            "-Xno-receiver-assertions",
+            "-Xopt-in=kotlin.RequiresOptIn"
+        )
+    }
+}
diff --git a/buildSrc/src/main/resources/META-INF/gradle-plugins/advent-of-code.properties b/buildSrc/src/main/resources/META-INF/gradle-plugins/advent-of-code.properties
new file mode 100644
index 0000000..17f9ebf
--- /dev/null
+++ b/buildSrc/src/main/resources/META-INF/gradle-plugins/advent-of-code.properties
@@ -0,0 +1 @@
+implementation-class=AdventOfCodePlugin
diff --git a/days/build.gradle.kts b/days/build.gradle.kts
new file mode 100644
index 0000000..99b6ef0
--- /dev/null
+++ b/days/build.gradle.kts
@@ -0,0 +1,7 @@
+plugins {
+    id("kotlin-convention")
+}
+
+dependencies {
+    implementation(project(":utils"))
+}
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..e708b1c
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..089b9f3
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.8-rc-1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
new file mode 100755
index 0000000..4f906e0
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,185 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=`expr $i + 1`
+    done
+    case $i in
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 0000000..ac1b06f
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/settings.gradle.kts b/settings.gradle.kts
new file mode 100644
index 0000000..b025579
--- /dev/null
+++ b/settings.gradle.kts
@@ -0,0 +1,3 @@
+rootProject.name = "aoc-2020"
+include("utils")
+include("days")
diff --git a/utils/build.gradle.kts b/utils/build.gradle.kts
new file mode 100644
index 0000000..7bf1894
--- /dev/null
+++ b/utils/build.gradle.kts
@@ -0,0 +1,3 @@
+plugins {
+    id("kotlin-convention")
+}
diff --git a/utils/src/main/kotlin/be/vandewalleh/aoc/utils/Resources.kt b/utils/src/main/kotlin/be/vandewalleh/aoc/utils/Resources.kt
new file mode 100644
index 0000000..f7de801
--- /dev/null
+++ b/utils/src/main/kotlin/be/vandewalleh/aoc/utils/Resources.kt
@@ -0,0 +1,27 @@
+@file:Suppress("unused", "MemberVisibilityCanBePrivate")
+
+package be.vandewalleh.aoc.utils
+
+import java.nio.file.Files
+import java.nio.file.Path
+import kotlin.streams.asSequence
+
+object Resources {
+    private fun path(name: String): Path {
+        val url = if (name.startsWith('/')) javaClass.getResource(name)
+        else javaClass.getResource("/$name")
+        return Path.of(url.toURI())
+    }
+
+    private fun Path.lines() = Files.lines(this)
+        .asSequence()
+        .filter { it.isNotBlank() }
+        .map { it.trim() }
+
+    private fun Path.text() = Files.readString(this).trim()
+
+    fun text(name: String) = path(name).text()
+    fun lines(name: String) = path(name).lines()
+    fun csv(name: String) = path(name).text().splitToSequence(",")
+    fun csvLong(name: String) = csv(name).map { it.toLong() }
+}