Reworked searches so they are in a Collections extensions file; linear search now works on any Iterable

Author: lillicoder

Diff for: search/src/main/kotlin/com/lillicoder/algorithms/search/Search.kt renamed to search/src/main/kotlin/com/lillicoder/algorithms/search/CollectionsKt.kt

@@ -1,38 +1,38 @@
-package com.lillicoder.algorithms.search
-
-/**
- * Performs a binary search on this list to find the position of the given element.
- * @param toFind Element to find.
- * @return List position or -1 if there is no such element.
- */
-fun <T : Comparable<T>> List<T>.binarySearch(toFind: T): Int {
-    var low = 0
-    var high = size - 1
-    while (low <= high) {
-        val middle = (low + high) ushr 1
-        val midElement = get(middle)
-
-        if (midElement == toFind) {
-            return middle
-        } else if (midElement < toFind) {
-            low = middle + 1
-        } else {
-            high = middle - 1
-        }
-    }
-
-    return -1
-}
-
-/**
- * Performs a linear search on this list to find the position of the given element.
- * @param toFind Element to find.
- * @return List position or -1 if there is no such element.
- */
-fun <T : Comparable<T>> List<T>.linearSearch(toFind: T): Int {
-    forEachIndexed { index, element ->
-        if (element == toFind) return index
-    }
-
-    return -1
-}
+package com.lillicoder.algorithms.search
+
+/**
+ * Performs a [linear search](https://en.wikipedia.org/wiki/Linear_search) to find the position of the given element.
+ * @param toFind Element to find.
+ * @return Position or -1 if there is no such element.
+ */
+fun <T : Comparable<T>> Iterable<T>.linearSearch(toFind: T): Int {
+    forEachIndexed { index, element ->
+        if (element == toFind) return index
+    }
+
+    return -1
+}
+
+/**
+ * Performs a [binary search](https://en.wikipedia.org/wiki/Binary_search) find the position of the given element.
+ * @param toFind Element to find.
+ * @return Position or -1 if there is no such element.
+ */
+fun <T : Comparable<T>> List<T>.binarySearch(toFind: T): Int {
+    var low = 0
+    var high = size - 1
+    while (low <= high) {
+        val middle = (low + high) ushr 1
+        val midElement = get(middle)
+
+        if (midElement == toFind) {
+            return middle
+        } else if (midElement < toFind) {
+            low = middle + 1
+        } else {
+            high = middle - 1
+        }
+    }
+
+    return -1
+}

Diff for: search/src/test/kotlin/com/lillicoder/algorithms/search/SearchTest.kt renamed to search/src/test/kotlin/com/lillicoder/algorithms/search/CollectionsKtTest.kt

@@ -1,25 +1,39 @@
-package com.lillicoder.algorithms.search
-
-import kotlin.test.Test
-import kotlin.test.assertEquals
-
-/**
- * Unit tests for list search extensions.
- */
-internal class SearchTest {
-    private val list = listOf("delta", "tau", "zeta", "alpha", "gamma", "alpha", "beta", "epsilon")
-
-    @Test
-    fun binarySearch() {
-        val expected = 6
-        val actual = list.sorted().binarySearch("tau")
-        assertEquals(expected, actual)
-    }
-
-    @Test
-    fun linearSearch() {
-        val expected = 3
-        val actual = list.linearSearch("alpha")
-        assertEquals(expected, actual)
-    }
-}
+package com.lillicoder.algorithms.search
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+/**
+ * Unit tests for list search extensions.
+ */
+internal class CollectionsKtTest {
+    private val list = listOf("delta", "tau", "zeta", "alpha", "gamma", "alpha", "beta", "epsilon")
+
+    @Test
+    fun `Binary search finds expected element`() {
+        val expected = 6
+        val actual = list.sorted().binarySearch("tau")
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `Binary search for invalid element returns -1`() {
+        val expected = -1
+        val actual = list.binarySearch("test")
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `Linear search finds expected element`() {
+        val expected = 3
+        val actual = list.linearSearch("alpha")
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `Linear search for invalid element returns -1`() {
+        val expected = -1
+        val actual = list.linearSearch("test")
+        assertEquals(expected, actual)
+    }
+}