From a7d7daf8552c7dbb19b7aeb7ee735ef53e63b7e3 Mon Sep 17 00:00:00 2001
From: Paulo <paulohenriquemoreirafalcao@gmail.com>
Date: Mon, 14 Oct 2024 19:03:26 -0300
Subject: [PATCH] feat(math): implement euclidean distance

---
 DIRECTORY.md                          |  1 +
 maths/euclidean_distance.ts           | 25 ++++++++++++++++
 maths/test/euclidean_distance.test.ts | 43 +++++++++++++++++++++++++++
 3 files changed, 69 insertions(+)
 create mode 100644 maths/euclidean_distance.ts
 create mode 100644 maths/test/euclidean_distance.test.ts

diff --git a/DIRECTORY.md b/DIRECTORY.md
index 185bae95..85c95c3e 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -109,6 +109,7 @@
   * [Degrees To Radians](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/degrees_to_radians.ts)
   * [Digit Sum](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/digit_sum.ts)
   * [Double Factorial Iterative](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/double_factorial_iterative.ts)
+  * [Euclidean Distance](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/euclidean_distance.ts)
   * [Euler Totient](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/euler_totient.ts)
   * [Factorial](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/factorial.ts)
   * [Factors](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/factors.ts)
diff --git a/maths/euclidean_distance.ts b/maths/euclidean_distance.ts
new file mode 100644
index 00000000..cbace917
--- /dev/null
+++ b/maths/euclidean_distance.ts
@@ -0,0 +1,25 @@
+/**
+ * @description Calculate the Euclidean distance between two vectors.
+ * @param {number[]} vectorA - The first vector.
+ * @param {number[]} vectorB - The second vector.
+ * @return {number} - The Euclidean distance between the two vectors.
+ * @throws Will throw an error if the vectors do not have the same dimensions.
+ * @see https://en.wikipedia.org/wiki/Euclidean_distance
+ * @example euclideanDistance([0, 0], [3, 4]) = 5
+ * @example euclideanDistance([1, 2, 3], [4, 5, 6]) = 5.196
+ */
+export const euclideanDistance = (
+  vectorA: number[],
+  vectorB: number[]
+): number => {
+  if (vectorA.length !== vectorB.length) {
+    throw new Error('Vectors must have the same dimensions')
+  }
+
+  let sum: number = 0
+  for (let index: number = 0; index < vectorA.length; index++) {
+    sum += (vectorA[index] - vectorB[index]) ** 2
+  }
+
+  return Math.sqrt(sum)
+}
diff --git a/maths/test/euclidean_distance.test.ts b/maths/test/euclidean_distance.test.ts
new file mode 100644
index 00000000..6e8158da
--- /dev/null
+++ b/maths/test/euclidean_distance.test.ts
@@ -0,0 +1,43 @@
+import { euclideanDistance } from '../euclidean_distance'
+
+describe('Euclidean distance', () => {
+  test.each([
+    [[0, 0], [0, 0], 0],
+    [[1, 0], [0, 0], 1],
+    [[0, 1], [0, 0], 1],
+    [[3, 4], [0, 0], 5],
+    [[1, 2, 3], [4, 5, 6], 5.196152422706632],
+    [[-1, -1], [1, 1], Math.sqrt(8)],
+    [[2, 3], [2, 3], 0]
+  ])('between %p and %p should be %f', (point1, point2, expected) => {
+    expect(euclideanDistance(point1, point2)).toBeCloseTo(expected)
+  })
+
+  test.each([
+    [[0, 0], [0]],
+    [[1], [1, 2]],
+    [
+      [1, 2, 3],
+      [4, 5]
+    ]
+  ])(
+    'should throw an error for mismatched dimensions %p and %p',
+    (point1, point2) => {
+      expect(() => euclideanDistance(point1, point2)).toThrowError(
+        'Vectors must have the same dimensions'
+      )
+    }
+  )
+
+  test('should handle empty vectors', () => {
+    expect(euclideanDistance([], [])).toBe(0)
+  })
+
+  test('should handle large vectors', () => {
+    const largeVector1 = Array(1000).fill(1)
+    const largeVector2 = Array(1000).fill(2)
+    expect(euclideanDistance(largeVector1, largeVector2)).toBeCloseTo(
+      Math.sqrt(1000)
+    )
+  })
+})