diff --git a/kotlin/custom-set/.exercism/metadata.json b/kotlin/custom-set/.exercism/metadata.json
new file mode 100644
index 0000000..d962d54
--- /dev/null
+++ b/kotlin/custom-set/.exercism/metadata.json
@@ -0,0 +1 @@
+{"track":"kotlin","exercise":"custom-set","id":"bae351839e7547ebb21a6dbc840e2b04","url":"https://exercism.io/my/solutions/bae351839e7547ebb21a6dbc840e2b04","handle":"anthonycicc","is_requester":true,"auto_approve":false}
\ No newline at end of file
diff --git a/kotlin/custom-set/.gradle/6.0.1/executionHistory/executionHistory.bin b/kotlin/custom-set/.gradle/6.0.1/executionHistory/executionHistory.bin
new file mode 100644
index 0000000..7fa0c37
Binary files /dev/null and b/kotlin/custom-set/.gradle/6.0.1/executionHistory/executionHistory.bin differ
diff --git a/kotlin/custom-set/.gradle/6.0.1/executionHistory/executionHistory.lock b/kotlin/custom-set/.gradle/6.0.1/executionHistory/executionHistory.lock
new file mode 100644
index 0000000..2233249
Binary files /dev/null and b/kotlin/custom-set/.gradle/6.0.1/executionHistory/executionHistory.lock differ
diff --git a/kotlin/custom-set/.gradle/6.0.1/fileChanges/last-build.bin b/kotlin/custom-set/.gradle/6.0.1/fileChanges/last-build.bin
new file mode 100644
index 0000000..f76dd23
Binary files /dev/null and b/kotlin/custom-set/.gradle/6.0.1/fileChanges/last-build.bin differ
diff --git a/kotlin/custom-set/.gradle/6.0.1/fileContent/fileContent.lock b/kotlin/custom-set/.gradle/6.0.1/fileContent/fileContent.lock
new file mode 100644
index 0000000..24c433c
Binary files /dev/null and b/kotlin/custom-set/.gradle/6.0.1/fileContent/fileContent.lock differ
diff --git a/kotlin/custom-set/.gradle/6.0.1/fileHashes/fileHashes.bin b/kotlin/custom-set/.gradle/6.0.1/fileHashes/fileHashes.bin
new file mode 100644
index 0000000..7f628b8
Binary files /dev/null and b/kotlin/custom-set/.gradle/6.0.1/fileHashes/fileHashes.bin differ
diff --git a/kotlin/custom-set/.gradle/6.0.1/fileHashes/fileHashes.lock b/kotlin/custom-set/.gradle/6.0.1/fileHashes/fileHashes.lock
new file mode 100644
index 0000000..8cd3633
Binary files /dev/null and b/kotlin/custom-set/.gradle/6.0.1/fileHashes/fileHashes.lock differ
diff --git a/kotlin/custom-set/.gradle/6.0.1/gc.properties b/kotlin/custom-set/.gradle/6.0.1/gc.properties
new file mode 100644
index 0000000..e69de29
diff --git a/kotlin/custom-set/.gradle/buildOutputCleanup/buildOutputCleanup.lock b/kotlin/custom-set/.gradle/buildOutputCleanup/buildOutputCleanup.lock
new file mode 100644
index 0000000..5f6a022
Binary files /dev/null and b/kotlin/custom-set/.gradle/buildOutputCleanup/buildOutputCleanup.lock differ
diff --git a/kotlin/custom-set/.gradle/buildOutputCleanup/cache.properties b/kotlin/custom-set/.gradle/buildOutputCleanup/cache.properties
new file mode 100644
index 0000000..2ea8b15
--- /dev/null
+++ b/kotlin/custom-set/.gradle/buildOutputCleanup/cache.properties
@@ -0,0 +1,2 @@
+#Sat Mar 07 17:31:28 EST 2020
+gradle.version=6.0.1
diff --git a/kotlin/custom-set/.gradle/buildOutputCleanup/outputFiles.bin b/kotlin/custom-set/.gradle/buildOutputCleanup/outputFiles.bin
new file mode 100644
index 0000000..c0268e2
Binary files /dev/null and b/kotlin/custom-set/.gradle/buildOutputCleanup/outputFiles.bin differ
diff --git a/kotlin/custom-set/.gradle/vcs-1/gc.properties b/kotlin/custom-set/.gradle/vcs-1/gc.properties
new file mode 100644
index 0000000..e69de29
diff --git a/kotlin/custom-set/.idea/.gitignore b/kotlin/custom-set/.idea/.gitignore
new file mode 100644
index 0000000..73f69e0
--- /dev/null
+++ b/kotlin/custom-set/.idea/.gitignore
@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml
+# Editor-based HTTP Client requests
+/httpRequests/
diff --git a/kotlin/custom-set/.idea/compiler.xml b/kotlin/custom-set/.idea/compiler.xml
new file mode 100644
index 0000000..7e7ee62
--- /dev/null
+++ b/kotlin/custom-set/.idea/compiler.xml
@@ -0,0 +1,6 @@
+
+
+
+
+
+
\ No newline at end of file
diff --git a/kotlin/custom-set/.idea/jarRepositories.xml b/kotlin/custom-set/.idea/jarRepositories.xml
new file mode 100644
index 0000000..efa4625
--- /dev/null
+++ b/kotlin/custom-set/.idea/jarRepositories.xml
@@ -0,0 +1,20 @@
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/kotlin/custom-set/.idea/misc.xml b/kotlin/custom-set/.idea/misc.xml
new file mode 100644
index 0000000..b9d0e72
--- /dev/null
+++ b/kotlin/custom-set/.idea/misc.xml
@@ -0,0 +1,8 @@
+
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/kotlin/custom-set/.idea/vcs.xml b/kotlin/custom-set/.idea/vcs.xml
new file mode 100644
index 0000000..b2bdec2
--- /dev/null
+++ b/kotlin/custom-set/.idea/vcs.xml
@@ -0,0 +1,6 @@
+
+
+
+
+
+
\ No newline at end of file
diff --git a/kotlin/custom-set/README.md b/kotlin/custom-set/README.md
new file mode 100644
index 0000000..f5dcb1b
--- /dev/null
+++ b/kotlin/custom-set/README.md
@@ -0,0 +1,35 @@
+# Custom Set
+
+Create a custom set type.
+
+Sometimes it is necessary to define a custom data structure of some
+type, like a set. In this exercise you will define your own set. How it
+works internally doesn't matter, as long as it behaves like a set of
+unique elements.
+
+## Setup
+
+Go through the setup instructions for Kotlin to install the necessary
+dependencies:
+
+[https://exercism.io/tracks/kotlin/installation](https://exercism.io/tracks/kotlin/installation)
+
+## Making the test suite pass
+
+Execute the tests with:
+
+```bash
+$ ./gradlew test
+```
+
+> Use `gradlew.bat` if you're on Windows
+
+In the test suites all tests but the first have been skipped.
+
+Once you get a test passing, you can enable the next one by removing the
+`@Ignore` annotation.
+
+## Submitting Incomplete Solutions
+
+It's possible to submit an incomplete solution so you can see how others have
+completed the exercise.
diff --git a/kotlin/custom-set/build.gradle.kts b/kotlin/custom-set/build.gradle.kts
new file mode 100644
index 0000000..1793ac4
--- /dev/null
+++ b/kotlin/custom-set/build.gradle.kts
@@ -0,0 +1,23 @@
+import org.gradle.api.tasks.testing.logging.TestExceptionFormat
+
+plugins {
+ kotlin("jvm") version "1.3.60"
+}
+
+repositories {
+ jcenter()
+}
+
+dependencies {
+ compile(kotlin("stdlib"))
+
+ testImplementation("junit:junit:4.12")
+ testImplementation(kotlin("test-junit"))
+}
+
+tasks.withType {
+ testLogging {
+ exceptionFormat = TestExceptionFormat.FULL
+ events("passed", "failed", "skipped")
+ }
+}
diff --git a/kotlin/custom-set/gradle/wrapper/gradle-wrapper.properties b/kotlin/custom-set/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..9492014
--- /dev/null
+++ b/kotlin/custom-set/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.0.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/kotlin/custom-set/gradlew b/kotlin/custom-set/gradlew
new file mode 100644
index 0000000..83f2acf
--- /dev/null
+++ b/kotlin/custom-set/gradlew
@@ -0,0 +1,188 @@
+#!/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`="\"$arg\""
+ fi
+ i=$((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"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+ cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/kotlin/custom-set/gradlew.bat b/kotlin/custom-set/gradlew.bat
new file mode 100644
index 0000000..9618d8d
--- /dev/null
+++ b/kotlin/custom-set/gradlew.bat
@@ -0,0 +1,100 @@
+@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 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 init
+
+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 init
+
+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
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+: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 %CMD_LINE_ARGS%
+
+: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/kotlin/custom-set/src/main/kotlin/CustomSet.kt b/kotlin/custom-set/src/main/kotlin/CustomSet.kt
new file mode 100644
index 0000000..78d79bf
--- /dev/null
+++ b/kotlin/custom-set/src/main/kotlin/CustomSet.kt
@@ -0,0 +1,42 @@
+class CustomSet() {
+
+ var internals = mutableSetOf()
+
+ constructor(vararg stuff: Int): this() {
+ stuff.forEach { this.add(it) }
+ }
+
+ constructor(wrapped: Set): this() {
+ wrapped.forEach { this.add(it) }
+ }
+
+ fun isEmpty(): Boolean = internals.isEmpty()
+
+ fun isSubset(other: CustomSet): Boolean = other.internals.containsAll(internals)
+
+ fun isDisjoint(other: CustomSet): Boolean {
+ return if (this.internals.isNotEmpty() && other.internals.isNotEmpty()) {
+ other.internals.all { it !in this.internals }
+ } else true
+ }
+
+ fun contains(other: Int): Boolean = this.internals.contains(other)
+
+ fun intersection(other: CustomSet): CustomSet = CustomSet(other.internals.intersect(this.internals))
+
+ fun add(other: Int) {
+ internals.add(other)
+ }
+
+ override fun equals(other: Any?) = if (other is CustomSet) {
+ other.internals == internals
+ } else {
+ false
+ }
+
+ operator fun plus(other: CustomSet) = CustomSet(internals.plus(other.internals))
+
+ operator fun minus(other: CustomSet) = CustomSet(this.internals.minus(other.internals))
+
+ override fun hashCode() = javaClass.hashCode()
+}
diff --git a/kotlin/custom-set/src/test/kotlin/CustomSetTest.kt b/kotlin/custom-set/src/test/kotlin/CustomSetTest.kt
new file mode 100644
index 0000000..1b8e041
--- /dev/null
+++ b/kotlin/custom-set/src/test/kotlin/CustomSetTest.kt
@@ -0,0 +1,286 @@
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertNotEquals
+import kotlin.test.assertTrue
+
+class CustomSetTest {
+
+ @Test
+ fun `sets with no elements are empty`() {
+ val sut = CustomSet()
+ assertTrue(sut.isEmpty())
+ }
+
+ @Test
+ fun `sets with elements are not empty`() {
+ val sut = CustomSet(1)
+ assertFalse(sut.isEmpty())
+ }
+
+ @Test
+ fun `nothing is contained in an empty set`() {
+ val sut = CustomSet()
+ assertFalse(sut.contains(1))
+ }
+
+ @Test
+ fun `when the element is in the set`() {
+ val sut = CustomSet(1, 2, 3)
+ assertTrue(sut.contains(1))
+ }
+
+ @Test
+ fun `when the element is not in the set`() {
+ val sut = CustomSet(1, 2, 3)
+ assertFalse(sut.contains(4))
+ }
+
+ @Test
+ fun `empty set is a subset of another empty set`() {
+ val set1 = CustomSet()
+ val set2 = CustomSet()
+ assertTrue(set1.isSubset(set2))
+ }
+
+ @Test
+ fun `empty set is a subset of non empty set`() {
+ val set1 = CustomSet()
+ val set2 = CustomSet(1)
+ assertTrue(set1.isSubset(set2))
+ }
+
+ @Test
+ fun `non empty set is not a subset of empty set`() {
+ val set1 = CustomSet(1)
+ val set2 = CustomSet()
+ assertFalse(set1.isSubset(set2))
+ }
+
+ @Test
+ fun `set is a subset of set with exact same elements`() {
+ val set1 = CustomSet(1, 2, 3)
+ val set2 = CustomSet(1, 2, 3)
+ assertTrue(set1.isSubset(set2))
+ }
+
+ @Test
+ fun `set is a subset of larger set with same elements`() {
+ val set1 = CustomSet(1, 2, 3)
+ val set2 = CustomSet(4, 1, 2, 3)
+ assertTrue(set1.isSubset(set2))
+ }
+
+ @Test
+ fun `set is not a subset of set that does not contain its elements`() {
+ val set1 = CustomSet(1, 2, 3)
+ val set2 = CustomSet(4, 1, 3)
+ assertFalse(set1.isSubset(set2))
+ }
+
+ @Test
+ fun `the empty set is disjoint with itself`() {
+ val set1 = CustomSet()
+ val set2 = CustomSet()
+ assertTrue(set1.isDisjoint(set2))
+ }
+
+ @Test
+ fun `empty set is disjoint with non empty set`() {
+ val set1 = CustomSet()
+ val set2 = CustomSet(1)
+ assertTrue(set1.isDisjoint(set2))
+ }
+
+ @Test
+ fun `non empty set is disjoint with empty set`() {
+ val set1 = CustomSet(1)
+ val set2 = CustomSet()
+ assertTrue(set1.isDisjoint(set2))
+ }
+
+ @Test
+ fun `sets are not disjoint if they share an element`() {
+ val set1 = CustomSet(1, 2)
+ val set2 = CustomSet(2, 3)
+ assertFalse(set1.isDisjoint(set2))
+ }
+
+ @Test
+ fun `sets are disjoint if they share no elements`() {
+ val set1 = CustomSet(1, 2)
+ val set2 = CustomSet(3, 4)
+ assertTrue(set1.isDisjoint(set2))
+ }
+
+ @Test
+ fun `empty sets are equal`() {
+ val set1 = CustomSet()
+ val set2 = CustomSet()
+ assertEquals(set1, set2)
+ }
+
+ @Test
+ fun `empty set is not equal to non empty set`() {
+ val set1 = CustomSet()
+ val set2 = CustomSet(1, 2, 3)
+ assertNotEquals(set1, set2)
+ }
+
+ @Test
+ fun `non empty set is not equal to empty set`() {
+ val set1 = CustomSet(1, 2, 3)
+ val set2 = CustomSet()
+ assertNotEquals(set1, set2)
+ }
+
+ @Test
+ fun `sets with the same elements are equal`() {
+ val set1 = CustomSet(1, 2)
+ val set2 = CustomSet(2, 1)
+ assertEquals(set1, set2)
+
+ }
+
+ @Test
+ fun `sets with different elements are not equal`() {
+ val set1 = CustomSet(1, 2, 3)
+ val set2 = CustomSet(1, 2, 4)
+ assertNotEquals(set1, set2)
+ }
+
+ @Test
+ fun `set is not equal to larger set with same elements`() {
+ val set1 = CustomSet(1, 2, 3)
+ val set2 = CustomSet(1, 2, 3, 4)
+ assertNotEquals(set1, set2)
+ }
+
+ @Test
+ fun `add to empty set`() {
+ val sut = CustomSet()
+ val expected = CustomSet(3)
+ sut.add(3)
+ assertEquals(expected, sut)
+ }
+
+ @Test
+ fun `add to non empty set`() {
+ val sut = CustomSet(1, 2, 4)
+ val expected = CustomSet(1, 2, 3, 4)
+ sut.add(3)
+ assertEquals(expected, sut)
+ }
+
+ @Test
+ fun `adding an existing element does not change the set`() {
+ val sut = CustomSet(1, 2, 3)
+ val expected = CustomSet(1, 2, 3)
+ sut.add(3)
+ assertEquals(expected, sut)
+ }
+
+ @Test
+ fun `intersection of two empty sets is an empty set`() {
+ val set1 = CustomSet()
+ val set2 = CustomSet()
+ val expected = CustomSet()
+ assertEquals(expected, set1.intersection(set2))
+ }
+
+ @Test
+ fun `intersection of an empty set and non empty set is an empty set`() {
+ val set1 = CustomSet()
+ val set2 = CustomSet(3, 2, 5)
+ val expected = CustomSet()
+ assertEquals(expected, set1.intersection(set2))
+ }
+
+ @Test
+ fun `intersection of a non empty set and an empty set is an empty set`() {
+ val set1 = CustomSet(1, 2, 3, 4)
+ val set2 = CustomSet()
+ val expected = CustomSet()
+ assertEquals(expected, set1.intersection(set2))
+ }
+
+ @Test
+ fun `intersection of two sets with no shared elements is an empty set`() {
+ val set1 = CustomSet(1, 2, 3)
+ val set2 = CustomSet(4, 5, 6)
+ val expected = CustomSet()
+ assertEquals(expected, set1.intersection(set2))
+ }
+
+ @Test
+ fun `intersection of two sets with shared elements is a set of the shared elements`() {
+ val set1 = CustomSet(1, 2, 3, 4)
+ val set2 = CustomSet(3, 2, 5)
+ val expected = CustomSet(2, 3)
+ assertEquals(expected, set1.intersection(set2))
+ }
+
+ @Test
+ fun `difference of two empty sets is an empty set`() {
+ val set1 = CustomSet()
+ val set2 = CustomSet()
+ val expected = CustomSet()
+ assertEquals(expected, set1 - set2)
+ }
+
+ @Test
+ fun `difference of empty set and non empty set is an empty set`() {
+ val set1 = CustomSet()
+ val set2 = CustomSet(3, 2, 5)
+ val expected = CustomSet()
+ assertEquals(expected, set1 - set2)
+ }
+
+ @Test
+ fun `difference of a non empty set and an empty set is the non empty set`() {
+ val set1 = CustomSet(1, 2, 3, 4)
+ val set2 = CustomSet()
+ val expected = CustomSet(1, 2, 3, 4)
+ assertEquals(expected, set1 - set2)
+ }
+
+ @Test
+ fun `difference of two non empty sets is a set of elements that are only in the first set`() {
+ val set1 = CustomSet(3, 2, 1)
+ val set2 = CustomSet(2, 4)
+ val expected = CustomSet(1, 3)
+ assertEquals(expected, set1 - set2)
+ }
+
+ @Test
+ fun `union of empty sets is an empty set`() {
+ val set1 = CustomSet()
+ val set2 = CustomSet()
+ val expected = CustomSet()
+ assertEquals(expected, set1 + set2)
+ }
+
+ @Test
+ fun `union of an empty set and non empty set is the non empty set`() {
+ val set1 = CustomSet()
+ val set2 = CustomSet(2)
+ val expected = CustomSet(2)
+ assertEquals(expected, set1 + set2)
+ }
+
+ @Test
+ fun `union of a non empty set and empty set is the non empty set`() {
+ val set1 = CustomSet(1, 3)
+ val set2 = CustomSet()
+ val expected = CustomSet(1, 3)
+ assertEquals(expected, set1 + set2)
+ }
+
+ @Test
+ fun `union of non empty sets contains all unique elements`() {
+ val set1 = CustomSet(1, 3)
+ val set2 = CustomSet(2, 3)
+ val expected = CustomSet(3, 2, 1)
+ assertEquals(expected, set1 + set2)
+ }
+}