Implement binarySearch method for UArrays (KT-27262)

2019-01-23 18:47:36 +03:00
parent 6cd9858147
commit 550c74bb6b
4 changed files with 292 additions and 1 deletions
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package test.collections
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+
+class UArrayJVMTest {
+    @Test
+    fun binarySearch() {
+
+        fun <A, E> testFailures(array: A, binarySearch: A.(E, Int, Int) -> Int, element: E, arraySize: Int) {
+            assertFailsWith<IllegalArgumentException> {
+                array.binarySearch(element, 1, 0)
+            }
+            assertFailsWith<IndexOutOfBoundsException> {
+                array.binarySearch(element, 1, arraySize + 1)
+            }
+            assertFailsWith<IndexOutOfBoundsException> {
+                array.binarySearch(element, -1, 1)
+            }
+        }
+
+        val array = uintArrayOf(1u, 0u, 4u, 5u, 8u, 12u, 2u, 3u, 7u, 7u, 7u, 9u, 2u)
+
+        testFailures(array.toUByteArray(), UByteArray::binarySearch, 0u, array.size)
+        testFailures(array.toUShortArray(), UShortArray::binarySearch, 0u, array.size)
+        testFailures(array, UIntArray::binarySearch, 0u, array.size)
+        testFailures(array.toULongArray(), ULongArray::binarySearch, 0u, array.size)
+
+        fun <A, E> test(
+            array: A,
+            binarySearch: A.(E, Int, Int) -> Int,
+            operations: List<OperationOnRange<UInt, Int>>,
+            transform: UInt.() -> E
+        ) {
+            operations.forEach { o ->
+                val result = array.binarySearch(o.element.transform(), o.fromIndex, o.toIndex)
+                assertEquals(o.expectedResult, result)
+            }
+        }
+
+        val operations = listOf(
+            OperationOnRange(0u, 1, 6, 1),
+            OperationOnRange(12u, 1, 6, 5),
+            OperationOnRange(8u, 1, 6, 4),
+            OperationOnRange(4u, 1, 6, 2),
+            OperationOnRange(5u, 2, 6, 3),
+            OperationOnRange(8u, 2, 5, 4),
+            OperationOnRange(5u, 3, 4, 3),
+
+            OperationOnRange(5u, 3, 3, -4),
+            OperationOnRange(7u, 1, 6, -5),
+            OperationOnRange(8u, 6, 12, -12),
+            OperationOnRange(5u, 6, 12, -9),
+
+            OperationOnRange(7u, 6, 12, 8)
+        )
+
+        test(array.toUByteArray(), UByteArray::binarySearch, operations, UInt::toUByte)
+        test(array.toUShortArray(), UShortArray::binarySearch, operations, UInt::toUShort)
+        test(array, UIntArray::binarySearch, operations, UInt::toUInt)
+        test(array.toULongArray(), ULongArray::binarySearch, operations, UInt::toULong)
+    }
+}
+
+
+private class OperationOnRange<E, R>(
+    val element: E,
+    val fromIndex: Int,
+    val toIndex: Int,
+    val expectedResult: R
+)
+
+
+private fun UIntArray.toUByteArray(): UByteArray {
+    return UByteArray(size) { get(it).toUByte() }
+}
+
+private fun UIntArray.toUShortArray(): UShortArray {
+    return UShortArray(size) { get(it).toUShort() }
+}
+
+private fun UIntArray.toULongArray(): ULongArray {
+    return ULongArray(size) { get(it).toULong() }
+}