Add Binary Search in list

Author: Romanow

README.md

@@ -63,9 +63,10 @@
 4. Quick Sort – [solution](src/main/kotlin/ru/romanow/algorithms/QuickSort.kt), [test](src/test/kotlin/ru/romanow/algorithms/QuickSortTest.kt)
 5. Merge Sort – [solution](src/main/kotlin/ru/romanow/algorithms/MergeSort.kt), [test](src/test/kotlin/ru/romanow/algorithms/MergeSortTest.kt)
 6. Binary Search Tree – [solution](src/main/kotlin/ru/romanow/algorithms/BinarySearchTree.kt), [test](src/test/kotlin/ru/romanow/algorithms/BinarySearchTreeTest.kt)
-7. Pre-order Deep First Search Traversal – [solution](src/main/kotlin/ru/romanow/algorithms/PreOrderDeepFirstSearch.kt), [test](src/test/kotlin/ru/romanow/algorithms/PreOrderDeepFirstSearchTest.kt)
-8. In-order Deep First Search Traversal – [solution](src/main/kotlin/ru/romanow/algorithms/InOrderDeepFirstSearch.kt), [test](src/test/kotlin/ru/romanow/algorithms/InOrderDeepFirstSearchTest.kt)
-9. Post-order Deep First Search Traversal – [solution](src/main/kotlin/ru/romanow/algorithms/PostOrderDeepFirstSearch.kt), [test](src/test/kotlin/ru/romanow/algorithms/PostOrderDeepFirstSearchTest.kt)
-10. Breadth First Search Traversal – [solution](src/main/kotlin/ru/romanow/algorithms/BreadthFirstSearch.kt), [test](src/test/kotlin/ru/romanow/algorithms/BreadthFirstSearchTest.kt)
+7. Binary Search List – [solution](src/main/kotlin/ru/romanow/algorithms/BinarySearchList.kt), [test](src/test/kotlin/ru/romanow/algorithms/BinarySearchListTest.kt)
+8. Pre-order Deep First Search Traversal – [solution](src/main/kotlin/ru/romanow/algorithms/PreOrderDeepFirstSearch.kt), [test](src/test/kotlin/ru/romanow/algorithms/PreOrderDeepFirstSearchTest.kt)
+9. In-order Deep First Search Traversal – [solution](src/main/kotlin/ru/romanow/algorithms/InOrderDeepFirstSearch.kt), [test](src/test/kotlin/ru/romanow/algorithms/InOrderDeepFirstSearchTest.kt)
+10. Post-order Deep First Search Traversal – [solution](src/main/kotlin/ru/romanow/algorithms/PostOrderDeepFirstSearch.kt), [test](src/test/kotlin/ru/romanow/algorithms/PostOrderDeepFirstSearchTest.kt)
+11. Breadth First Search Traversal – [solution](src/main/kotlin/ru/romanow/algorithms/BreadthFirstSearch.kt), [test](src/test/kotlin/ru/romanow/algorithms/BreadthFirstSearchTest.kt)
 
 [//]: # (@formatter:on)

src/main/kotlin/ru/romanow/algorithms/BinarySearchList.kt

@@ -0,0 +1,15 @@
+package ru.romanow.algorithms
+
+class BinarySearchList {
+    fun find(list: List<Int>, target: Int, left: Int = 0, right: Int = list.size - 1): Int {
+        if (left > right) {
+            return -1
+        }
+        val middle = left + (right - left) / 2
+        return when {
+            list[middle] == target -> middle
+            list[middle] < target -> find(list, target, middle + 1, right)
+            else -> find(list, target, left, middle - 1)
+        }
+    }
+}

src/test/kotlin/ru/romanow/algorithms/BinarySearchListTest.kt

@@ -0,0 +1,27 @@
+package ru.romanow.algorithms
+
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.api.extension.ExtensionContext
+import org.junit.jupiter.params.ParameterizedTest
+import org.junit.jupiter.params.provider.Arguments
+import org.junit.jupiter.params.provider.ArgumentsProvider
+import org.junit.jupiter.params.provider.ArgumentsSource
+import java.util.stream.Stream
+
+class BinarySearchListTest {
+
+    @ArgumentsSource(ValueProvider::class)
+    @ParameterizedTest(name = "#{index} – Search {1} in tree {0}")
+    fun flatten(list: List<Int>, target: Int, result: Int?) {
+        val obj = BinarySearchList()
+        assertThat(obj.find(list, target)).isEqualTo(result)
+    }
+
+    internal class ValueProvider : ArgumentsProvider {
+        override fun provideArguments(context: ExtensionContext): Stream<Arguments> =
+            Stream.of(
+                Arguments.of(listOf(1, 3, 5, 7, 10, 12, 15), 3, 1),
+                Arguments.of(listOf(1, 3, 5, 7, 10, 12, 15), 14, -1)
+            )
+    }
+}

src/test/kotlin/ru/romanow/algorithms/BinarySearchTreeTest.kt

@@ -13,10 +13,8 @@ class BinarySearchTreeTest {
 
     @ArgumentsSource(ValueProvider::class)
     @ParameterizedTest(name = "#{index} – Search {1} in tree {0}")
-    fun flatten(items: List<Int?>, target: Int, result: Int?) {
+    fun flatten(items: List<Int>, target: Int, result: Int?) {
         val root = buildTreeFromList(items)
-        // printTree(root)
-
         val obj = BinarySearchTree()
         assertThat(obj.find(root, target)?.value).isEqualTo(result)
     }