I am working on the Custom Set (Easy!) exercise, but am unable to get it to work. I am debugging in IntelliJ’s IDEA, and it is flagging the error. But when I compare the difference between my output and the expected output, it is showing that both outputs are identical. So I’m unable to complete this exercise.
Here is my code:
class CustomSet(vararg all: Int) {
private var s: MutableSet<Int> = mutableSetOf<Int>()
private var size = 0
init {
for (i in all) {
s.add(i)
}
s = s.toSortedSet()
size = s.size
}
override fun toString(): String {
val x = s.toSet().sorted().joinToString(prefix = "[", postfix = "]")
return x
}
override fun hashCode(): Int {
return s.hashCode()
}
fun isEmpty(): Boolean {
return s.isEmpty()
}
fun isSubset(other: CustomSet): Boolean {
if (this.isEmpty()) return true
for (i in 0 until size) {
if (!other.containsAll(this)) {
// if (i !in s) {
return false
}
}
return true
}
fun isDisjoint(other: CustomSet): Boolean {
if (this.isEmpty() || other.isEmpty()) return true
for (i in this.s) {
if (other.contains(i)) {
return false
}
}
return true
}
fun contains(other: Int): Boolean {
return s.contains(other)
}
fun containsAll(other: CustomSet): Boolean {
return s.containsAll(other.s)
}
fun intersection(other: CustomSet): CustomSet {
val t = CustomSet()
for (i in s) {
if (other.s.contains(i)) {
t.add(i)
}
}
return t
}
fun add(other: Int) {
s.add(other)
}
override fun equals(other: Any?): Boolean {
if (listOf(other).size != s.size) return false
for (i in listOf(other)) {
if (i !in s) return false
}
for (i in s) {
if (i !in listOf(other)) return false
}
return true
}
operator fun plus(other: CustomSet): CustomSet {
val t: CustomSet = this
for (i in 0 until other.size) {
if (!t.contains(other[i])) t.add(other[i])
}
return t
}
private operator fun get(i: Int): Int {
return i
}
operator fun minus(other: CustomSet): CustomSet {
val t = this
for (i in 0 until other.size) {
if (t.s.contains(other[i])) {
t.s.remove(other[i])
}
}
return t
}
java.lang.AssertionError: expected: CustomSet<> but was: CustomSet<>
at org.junit.Assert.fail(Assert.java:89)
at org.junit.Assert.failNotEquals(Assert.java:835)
at org.junit.Assert.assertEquals(Assert.java:120)
at kotlin.test.junit.JUnitAsserter.assertEquals(JUnitSupport.kt:32)
at kotlin.test.AssertionsKt__AssertionsKt.assertEquals(Assertions.kt:63)
at kotlin.test.AssertionsKt.assertEquals(Unknown Source)
at kotlin.test.AssertionsKt__AssertionsKt.assertEquals$default(Assertions.kt:62)
at kotlin.test.AssertionsKt.assertEquals$default(Unknown Source)
at CustomSetTest.intersection of a non empty set and an empty set is an empty set(CustomSetTest.kt:204)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.runTestClass(JUnitTestClassExecutor.java:112)
at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:58)
at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:40)
at org.gradle.api.internal.tasks.testing.junit.AbstractJUnitTestClassProcessor.processTestClass(AbstractJUnitTestClassProcessor.java:60)
at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:52)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
at com.sun.proxy.$Proxy2.processTestClass(Unknown Source)
at org.gradle.api.internal.tasks.testing.worker.TestWorker$2.run(TestWorker.java:176)
at org.gradle.api.internal.tasks.testing.worker.TestWorker.executeAndMaintainThreadName(TestWorker.java:129)
at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:100)
at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:60)
at org.gradle.process.internal.worker.child.ActionExecutionWorker.execute(ActionExecutionWorker.java:56)
at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:113)
at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:65)
at worker.org.gradle.process.internal.worker.GradleWorkerMain.run(GradleWorkerMain.java:69)
at worker.org.gradle.process.internal.worker.GradleWorkerMain.main(GradleWorkerMain.java:74)
private var s: MutableSet<Int> = mutableSetOf<Int>()
private var size = 0
init {
for (i in all) {
s.add(i)
}
s = s.toSortedSet()
size = s.size
}
override fun toString(): String {
val x = s.toSet().sorted().joinToString(prefix = "[", postfix = "]")
return x
}
override fun hashCode(): Int {
return s.hashCode()
}
fun isEmpty(): Boolean {
return s.isEmpty()
}
fun isSubset(other: CustomSet): Boolean {
if (this.isEmpty()) return true
for (i in 0 until size) {
if (!other.containsAll(this)) {
// if (i !in s) {
return false
}
}
return true
}
fun isDisjoint(other: CustomSet): Boolean {
if (this.isEmpty() || other.isEmpty()) return true
for (i in this.s) {
if (other.contains(i)) {
return false
}
}
return true
}
fun contains(other: Int): Boolean {
return s.contains(other)
}
fun containsAll(other: CustomSet): Boolean {
return s.containsAll(other.s)
}
fun intersection(other: CustomSet): CustomSet {
val t = CustomSet()
for (i in s) {
if (other.s.contains(i)) {
t.add(i)
}
}
return t
}
fun add(other: Int) {
s.add(other)
}
override fun equals(other: Any?): Boolean {
if (listOf(other).size != s.size) return false
for (i in listOf(other)) {
if (i !in s) return false
}
for (i in s) {
if (i !in listOf(other)) return false
}
return true
}
operator fun plus(other: CustomSet): CustomSet {
val t: CustomSet = this
for (i in 0 until other.size) {
if (!t.contains(other[i])) t.add(other[i])
}
return t
}
private operator fun get(i: Int): Int {
return i
}
operator fun minus(other: CustomSet): CustomSet {
val t = this
for (i in 0 until other.size) {
if (t.s.contains(other[i])) {
t.s.remove(other[i])
}
}
return t
}
I suspect you have a bug in equals. A simpler way to think of two sets being equal: same size and one is a subset of the other – an opportunity for code reuse.
Will update the equals function.