Hashing: Jewels and Stones

Author: jhonnymoreira

README.md

@@ -17,7 +17,7 @@
   - [x] [Maximum Number of Balloons](./src/hashing/maximum-number-of-balloons.ts)
   - [x] [Contiguous Array](./src/hashing/contiguous-array.ts)
   - [x] [Ransom Note](./src/hashing/ransom-note.ts)
-  - [ ] [Jewels and Stones](./src/hashing/jewels-and-stones.ts)
+  - [x] [Jewels and Stones](./src/hashing/jewels-and-stones.ts)
   - [ ] [Longest Substring Without Repeating Characters](./src/hashing/longest-substring-without-repeating-characters.ts)
 - [ ] Linked Lists
   - [ ] [Middle of the Linked List](./src/linked-lists/middle-of-the-linked-list.ts)

src/hashing/jewels-and-stones.ts

@@ -1 +1,12 @@
-export function () {}
+export function numJewelsInStones(jewels: string, stones: string): number {
+  const availableJews = new Set(jewels);
+
+  let totalJewels = 0;
+  for (const stone of stones) {
+    if (availableJews.has(stone)) {
+      totalJewels++;
+    }
+  }
+
+  return totalJewels;
+}

tests/hashing/jewels-and-stones.test.ts

@@ -1,3 +1,26 @@
-import {} from '@/hashing/jewels-and-stones.js';
+import { numJewelsInStones } from '@/hashing/jewels-and-stones.js';
 
-describe.todo('Hashing: Jewels and Stones')
+describe('Hashing: Jewels and Stones', () => {
+  test.each([
+    {
+      jewels: 'aA',
+      stones: 'aAAbbbb',
+      output: 3,
+    },
+    {
+      jewels: 'z',
+      stones: 'ZZ',
+      output: 0,
+    },
+    {
+      jewels: 'k',
+      stones: 'abcD',
+      output: 0,
+    },
+  ])(
+    'numJewelsInStones($jewels, $stones) === $output',
+    ({ jewels, stones, output }) => {
+      expect(numJewelsInStones(jewels, stones)).toStrictEqual(output);
+    }
+  );
+});