211th Commit

README.md

@@ -221,14 +221,15 @@ Ace Coding Interview with 75 Qs
 [1926]: ./src/page-18/1926.%20Nearest%20Exit%20from%20Entrance%20in%20Maze/nearestExit.ts
 [994]: ./src/page-10/994.%20Rotting%20Oranges/orangesRotting.ts
 
-| Heap / Priority Queue                 |                 |        |
-| ------------------------------------- | --------------- | ------ |
-| 215. Kth Largest Element in an Array  | [Solution][215] | Medium |
-| 2336. Smallest Number in Infinite Set | Solution        | Medium |
-| 2542. Maximum Subsequence Score       | Solution        | Medium |
-| 2462. Total Cost to Hire K Workers    | Solution        | Medium |
+| Heap / Priority Queue                 |                  |        |
+| ------------------------------------- | ---------------- | ------ |
+| 215. Kth Largest Element in an Array  | [Solution][215]  | Medium |
+| 2336. Smallest Number in Infinite Set | [Solution][2336] | Medium |
+| 2542. Maximum Subsequence Score       | Solution         | Medium |
+| 2462. Total Cost to Hire K Workers    | Solution         | Medium |
 
 [215]: ./src/page-2/215.%20Kth%20Largest%20Element%20in%20an%20Array/findKthLargest.ts
+[2336]: ./src/page-22/2336.%20Smallest%20Number%20in%20Infinite%20Set/SmallestInfiniteSet.ts
 
 | Binary Search                                |          |        |
 | -------------------------------------------- | -------- | ------ |

src/page-22/2336. Smallest Number in Infinite Set/SmallestInfiniteSet.test.ts

@@ -0,0 +1,15 @@
+import { SmallestInfiniteSet } from './SmallestInfiniteSet';
+
+describe('2336. Smallest Number in Infinite Set', () => {
+  test('SmallestInfiniteSet', () => {
+    const smallestInfiniteSet = new SmallestInfiniteSet();
+    smallestInfiniteSet.addBack(2);
+    expect(smallestInfiniteSet.popSmallest()).toBe(1);
+    expect(smallestInfiniteSet.popSmallest()).toBe(2);
+    expect(smallestInfiniteSet.popSmallest()).toBe(3);
+    smallestInfiniteSet.addBack(1);
+    expect(smallestInfiniteSet.popSmallest()).toBe(1);
+    expect(smallestInfiniteSet.popSmallest()).toBe(4);
+    expect(smallestInfiniteSet.popSmallest()).toBe(5);
+  });
+});

src/page-22/2336. Smallest Number in Infinite Set/SmallestInfiniteSet.ts

@@ -0,0 +1,38 @@
+/**
+ * Accepted
+ */
+export class SmallestInfiniteSet {
+  private minHeap: number[];
+  private addedBack: Set<number>;
+  private current: number;
+
+  constructor() {
+    this.minHeap = [];
+    this.addedBack = new Set();
+    this.current = 1;
+  }
+
+  popSmallest(): number {
+    if (this.minHeap.length > 0) {
+      const smallest = this.minHeap.shift();
+
+      if (smallest !== undefined) {
+        this.addedBack.delete(smallest);
+        return smallest;
+      }
+    }
+
+    // If heap is empty, return the current smallest number in sequence
+    const smallest = this.current;
+    this.current += 1; // Manually increment current
+    return smallest;
+  }
+
+  addBack(num: number): void {
+    if (num < this.current && !this.addedBack.has(num)) {
+      this.minHeap.push(num);
+      this.minHeap.sort((a, b) => a - b); // Ensure heap property
+      this.addedBack.add(num);
+    }
+  }
+}