Ilya Matveev
63 lines
1.7 KiB
Kotlin
63 lines
1.7 KiB
Kotlin
class TestCollection(): AbstractMutableCollection<Int>() {
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companion object {
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const val SIZE = 7
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}
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private val array = IntArray(SIZE)
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private var len = 0
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override val size: Int
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get() = len
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override fun add(element: Int): Boolean {
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if (len >= SIZE) return false
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array[len++] = element
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return true
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}
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override fun iterator(): MutableIterator<Int> = object: MutableIterator<Int> {
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var nextIndex = 0
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override fun hasNext() = nextIndex < len
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override fun next() = array[nextIndex++]
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override fun remove() {
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if (nextIndex == 0) throw IllegalStateException()
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for (i in nextIndex..len - 1) {
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array[i - 1] = array[i]
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}
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len--
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nextIndex--
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}
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}
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override fun clear() {
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len = 0
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}
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}
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fun assertEquals(a: TestCollection, b: List<Int>) {
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if (a.size != b.size) {
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throw AssertionError()
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}
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val aIt = a.iterator()
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val bIt = b.iterator()
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while (aIt.hasNext()) {
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if (aIt.next() != bIt.next()) throw AssertionError("TestCollection contains wrong elements. Expected: $b, actual: $a.")
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}
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}
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fun main(args: Array<String>) {
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val c = TestCollection()
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if (!c.addAll(listOf(1, 2, 3, 2, 4, 5, 4))) throw AssertionError("addAll is false when it must be true.")
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if (c.addAll(listOf(1, 2)) != false) throw AssertionError("addAll is true when it must be false.")
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c.removeAll(listOf(1, 2))
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assertEquals(c, listOf(3, 4, 5, 4))
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c.retainAll(listOf(4, 5))
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assertEquals(c, listOf(4, 5, 4))
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c.remove(4)
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assertEquals(c, listOf(5, 4))
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c.clear()
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assertEquals(c, listOf())
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} |