https://leetcode.cn/problems/design-a-file-sharing-system/

Author: masx200

README.md

@@ -45,6 +45,8 @@ Step 2. Add the dependency
 
 <summary>展开查看</summary>
 
+https://leetcode.cn/problems/design-a-file-sharing-system/
+
 https://leetcode.cn/problems/append-k-integers-with-minimal-sum/
 
 https://leetcode.cn/problems/inorder-successor-in-bst-ii/

design-a-file-sharing-system/index.ts

@@ -0,0 +1,65 @@
+export default class FileSharing {
+    #chunkUsersMap = new Map<number, Set<number>>();
+
+    #userChunksMap = new Map<number, Set<number>>();
+    #userQueue = new BinaryHeap<number>((a, b) => a - b);
+    #maxUser = 0;
+    constructor(_m: number) {}
+
+    join(ownedChunks: number[]): number {
+        let userID = 0;
+
+        if (this.#userQueue.isEmpty()) {
+            this.#maxUser++;
+            userID = this.#maxUser;
+        } else {
+            userID = this.#userQueue.pop() as number;
+        }
+
+        for (const chunk of ownedChunks) {
+            const users = this.#chunkUsersMap.get(chunk) ?? new Set();
+            users.add(userID);
+            this.#chunkUsersMap.set(chunk, users);
+        }
+        this.#userChunksMap.set(userID, new Set(ownedChunks));
+        return userID;
+    }
+    leave(userID: number) {
+        if (this.#userChunksMap.has(userID)) {
+            const chunks = this.#userChunksMap.get(userID) ?? [];
+            for (const chunk of chunks) {
+                if (this.#chunkUsersMap.has(chunk)) {
+                    const users = this.#chunkUsersMap.get(chunk) as Set<number>;
+                    users.delete(userID);
+                    if (users.size > 0) this.#chunkUsersMap.set(chunk, users);
+                    else this.#chunkUsersMap.delete(chunk);
+                }
+            }
+            this.#userChunksMap.delete(userID);
+        }
+
+        this.#userQueue.push(userID);
+    }
+
+    request(userID: number, chunkID: number): Array<number> {
+        const usersList = Array<number>();
+        if (
+            !this.#chunkUsersMap.has(chunkID) || !this.#userChunksMap.has(userID)
+        ) return [];
+
+        usersList.push(...(this.#chunkUsersMap.get(chunkID) ?? []));
+
+        const users = this.#chunkUsersMap.get(chunkID) as Set<number>;
+        users.add(userID);
+
+        this.#chunkUsersMap.set(chunkID, users);
+
+        const chunks = this.#userChunksMap.get(userID) as Set<number>;
+
+        chunks.add(chunkID);
+        this.#userChunksMap.set(userID, chunks);
+        usersList.sort((a, b) => a - b);
+        return usersList;
+    }
+}
+import { BinaryHeap } from "https://deno.land/[email protected]/collections/binary_heap.ts";

design-a-file-sharing-system/test.ts

@@ -0,0 +1,37 @@
+import { assertEquals } from "asserts";
+import { runScript } from "leetcode-class";
+
+import FileSharing from "./index.ts";
+
+Deno.test("design-a-file-sharing-system", () => {
+    assertEquals(
+        runScript(
+            [
+                "FileSharing",
+                "join",
+                "join",
+                "join",
+                "request",
+                "request",
+                "leave",
+                "request",
+                "leave",
+                "join",
+            ],
+            [
+                [4],
+                [[1, 2]],
+                [[2, 3]],
+                [[4]],
+                [1, 3],
+                [2, 2],
+                [1],
+                [2, 1],
+                [2],
+                [[]],
+            ],
+            FileSharing,
+        ),
+        [null, 1, 2, 3, [2], [1, 2], null, [], null, 1],
+    );
+});