Add linear search algorithm implementation with tests and documentation

Author: toramanomer

README.md

@@ -0,0 +1,8 @@
+# Linear Search
+
+Linear search is a searching algorithm that sequentially checks each element in a list until the desired element is found or the sequence ends.
+
+## Time Complexity
+
+-   **Best Case:** **O(1)** (Element found at the beginning)
+-   **Worst Case:** **O(n)** (Element at the end or not present)

src/algorithms/searching/linearSearch.ts

@@ -0,0 +1,12 @@
+export const linearSearch = <T>(
+	array: T[],
+	target: T
+): { index: number; element: T } | null => {
+	const length = array.length
+	for (let index = 0; index < length; index++) {
+		const element = array[index]
+		if (element === target) return { index, element }
+	}
+
+	return null
+}

tests/algorithms/searching/linearSearch.test.ts

@@ -0,0 +1,50 @@
+import { describe, it, expect } from 'vitest'
+import { linearSearch } from '../../../src/algorithms/searching/linearSearch'
+
+describe('linearSearch', () => {
+	describe('when the array is empty', () => {
+		it('should return null', () => {
+			expect(linearSearch([], 1)).toBeNull()
+		})
+	})
+
+	describe('when the target is in the list', () => {
+		it('should return the target with its index', () => {
+			const vectors = [
+				{
+					array: [0, 1, 2, 3, 4, 5],
+					target: 1,
+					expected: { index: 1, element: 1 }
+				},
+				{
+					array: [5, 4, 3, 2, 1, 0],
+					target: 1,
+					expected: { index: 4, element: 1 }
+				}
+			]
+			vectors.forEach(({ array, target, expected }) => {
+				expect(linearSearch(array, target)).toStrictEqual(expected)
+			})
+		})
+	})
+
+	describe('when the target is not in the list', () => {
+		it('it should return null', () => {
+			const vectors = [
+				{
+					array: [0, 1, 2, 3, 4, 5],
+					target: 6,
+					expected: null
+				},
+				{
+					array: [5, 4, 3, 2, 1, 0],
+					target: 6,
+					expected: null
+				}
+			]
+			vectors.forEach(({ array, target, expected }) => {
+				expect(linearSearch(array, target)).toBeNull()
+			})
+		})
+	})
+})