feat: array chunk algorithm

Author: francislagares

src/algorithms/array-chunk/array-chunk.ts

@@ -0,0 +1,29 @@
+// Option 1
+export const chunkArray = (arr: number[], size: number) => {
+  const chunked = [];
+
+  for (const element of arr) {
+    const last = chunked[chunked.length - 1];
+
+    if (!last || last.length === size) {
+      chunked.push([element]);
+    } else {
+      last.push(element);
+    }
+  }
+
+  return chunked;
+};
+
+// Option 2
+export const chunkSliced = (arr: number[], size: number) => {
+  const chunked = [];
+  let index = 0;
+
+  while (index < arr.length) {
+    chunked.push(arr.slice(index, index + size));
+    index += size;
+  }
+
+  return chunked;
+};

src/algorithms/array-chunk/tests/array-chunk.test.ts

@@ -0,0 +1,71 @@
+import { describe, test } from 'vitest';
+import { chunkArray, chunkSliced } from '../array-chunk';
+
+describe('Array chunk', () => {
+  test('function chunkArray exists', () => {
+    expect(typeof chunkArray).toEqual('function');
+    expect(typeof chunkSliced).toEqual('function');
+  });
+
+  test('chunkArray divides an array of 10 elements with chunk size 2', () => {
+    const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+    const chunked = chunkArray(arr, 2);
+    const sliced = chunkSliced(arr, 2);
+
+    expect(chunked).toEqual([
+      [1, 2],
+      [3, 4],
+      [5, 6],
+      [7, 8],
+      [9, 10],
+    ]);
+    expect(sliced).toEqual([
+      [1, 2],
+      [3, 4],
+      [5, 6],
+      [7, 8],
+      [9, 10],
+    ]);
+  });
+
+  test('chunkArray divides an array of 3 elements with chunk size 1', () => {
+    const arr = [1, 2, 3];
+    const chunked = chunkArray(arr, 1);
+    const sliced = chunkSliced(arr, 1);
+
+    expect(chunked).toEqual([[1], [2], [3]]);
+    expect(sliced).toEqual([[1], [2], [3]]);
+  });
+
+  test('chunkArray divides an array of 5 elements with chunk size 3', () => {
+    const arr = [1, 2, 3, 4, 5];
+    const chunked = chunkArray(arr, 3);
+    const sliced = chunkSliced(arr, 3);
+
+    expect(chunked).toEqual([
+      [1, 2, 3],
+      [4, 5],
+    ]);
+    expect(sliced).toEqual([
+      [1, 2, 3],
+      [4, 5],
+    ]);
+  });
+
+  test('chunkArray divides an array of 13 elements with chunk size 5', () => {
+    const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13];
+    const chunked = chunkArray(arr, 5);
+    const sliced = chunkSliced(arr, 5);
+
+    expect(chunked).toEqual([
+      [1, 2, 3, 4, 5],
+      [6, 7, 8, 9, 10],
+      [11, 12, 13],
+    ]);
+    expect(sliced).toEqual([
+      [1, 2, 3, 4, 5],
+      [6, 7, 8, 9, 10],
+      [11, 12, 13],
+    ]);
+  });
+});