feat: leetcode 710

Author: deweyou

README.md

@@ -2,7 +2,7 @@
 
 <p align="center">
 <!-- TOPICS COUNT START -->
-<img src="https://img.shields.io/badge/-进度:413-green" alt="进度:413">
+<img src="https://img.shields.io/badge/-进度:414-green" alt="进度:414">
 <!-- TOPICS COUNT END -->
 <a href="./assets/docs/TOPICS.md"><img src="https://img.shields.io/badge/-题库目录-blue" alt="题库目录"></a>
 <a href="./assets/docs/CATEGORIES.md"><img src="https://img.shields.io/badge/-题库分类-red" alt="题库分类"></a>

assets/data/categories.json

@@ -206,6 +206,12 @@
         "path": "./problemset/two-sum-iv-input-is-a-bst/README.md",
         "difficulty": "简单"
       },
+      {
+        "id": "710",
+        "title": "黑名单中的随机数",
+        "path": "./problemset/random-pick-with-blacklist/README.md",
+        "difficulty": "困难"
+      },
       {
         "id": "720",
         "title": "词典中最长的单词",

assets/data/topics.json

@@ -3239,6 +3239,16 @@
     "url": "https://leetcode-cn.com/problems/to-lower-case/",
     "path": "./problemset/to-lower-case/README.md"
   },
+  {
+    "id": "710",
+    "title": {
+      "cn": "黑名单中的随机数",
+      "en": "random-pick-with-blacklist"
+    },
+    "difficulty": "困难",
+    "url": "https://leetcode.cn/problems/random-pick-with-blacklist/",
+    "path": "./problemset/random-pick-with-blacklist/README.md"
+  },
   {
     "id": "713",
     "title": {

assets/docs/CATEGORIES.md

@@ -38,6 +38,7 @@
 | 532. [数组中的 k-diff 数对](../../problemset/k-diff-pairs-in-an-array/README.md) | 中等 |
 | 599. [两个列表的最小索引总和](../../problemset/minimum-index-sum-of-two-lists/README.md) | 简单 |
 | 653. [两数之和 IV - 输入 BST](../../problemset/two-sum-iv-input-is-a-bst/README.md) | 简单 |
+| 710. [黑名单中的随机数](../../problemset/random-pick-with-blacklist/README.md) | 困难 |
 | 720. [词典中最长的单词](../../problemset/longest-word-in-dictionary/README.md) | 简单 |
 | 804. [唯一摩尔斯密码词](../../problemset/unique-morse-code-words/README.md) | 简单 |
 | 819. [最常见的单词](../../problemset/most-common-word/README.md) | 简单 |

assets/docs/TOPICS.md

@@ -648,6 +648,8 @@
 
 [709. 转换成小写字母](../../problemset/to-lower-case/README.md)
 
+[710. 黑名单中的随机数](../../problemset/random-pick-with-blacklist/README.md)
+
 [713. 乘积小于 K 的子数组](../../problemset/subarray-product-less-than-k/README.md)
 
 [715. Range模块](../../problemset/range-module/README.md)

problemset/random-pick-with-blacklist/README.md

@@ -0,0 +1,38 @@
+# 黑名单中的随机数
+
+> 难度：困难
+>
+> https://leetcode.cn/problems/random-pick-with-blacklist/
+
+## 题目
+
+给定一个整数 `n` 和一个 `无重复` 黑名单整数数组 `blacklist` 。设计一种算法，从 `[0, n - 1]` 范围内的任意整数中选取一个 **未加入** 黑名单 `blacklist` 的整数。任何在上述范围内且不在黑名单 `blacklist` 中的整数都应该有 **同等的可能性** 被返回。
+
+优化你的算法，使它最小化调用语言 **内置** 随机函数的次数。
+
+实现 `Solution` 类:
+
+- Solution(int n, int[] blacklist) 初始化整数 n 和被加入黑名单 blacklist 的整数
+- int pick() 返回一个范围为 [0, n - 1] 且不在黑名单 blacklist 中的随机整数
+ 
+
+### 示例：
+
+```
+输入
+["Solution", "pick", "pick", "pick", "pick", "pick", "pick", "pick"]
+[[7, [2, 3, 5]], [], [], [], [], [], [], []]
+输出
+[null, 0, 4, 1, 6, 1, 0, 4]
+
+解释
+Solution solution = new Solution(7, [2, 3, 5]);
+solution.pick(); // 返回0，任何[0,1,4,6]的整数都可以。注意，对于每一个pick的调用，
+                 // 0、1、4和6的返回概率必须相等(即概率为1/4)。
+solution.pick(); // 返回 4
+solution.pick(); // 返回 1
+solution.pick(); // 返回 6
+solution.pick(); // 返回 1
+solution.pick(); // 返回 0
+solution.pick(); // 返回 4
+```

problemset/random-pick-with-blacklist/index.spec.ts

@@ -0,0 +1,12 @@
+import { expect, it } from 'vitest'
+import { Solution } from '.'
+
+it('黑名单中的随机数', () => {
+  const solution = new Solution(7, [2, 3, 5])
+  expect([0, 1, 4, 6]).toContain(solution.pick())
+  expect([0, 1, 4, 6]).toContain(solution.pick())
+  expect([0, 1, 4, 6]).toContain(solution.pick())
+  expect([0, 1, 4, 6]).toContain(solution.pick())
+  expect([0, 1, 4, 6]).toContain(solution.pick())
+  expect([0, 1, 4, 6]).toContain(solution.pick())
+})

problemset/random-pick-with-blacklist/index.ts

@@ -0,0 +1,31 @@
+export class Solution {
+  bound: number
+  b2w: Map<number, number>
+
+  constructor(n: number, blacklist: number[]) {
+    this.b2w = new Map<number, number>()
+    const len = blacklist.length
+    this.bound = n - len
+    const black = new Set()
+
+    for (const b of blacklist) {
+      if (b >= this.bound)
+        black.add(b)
+    }
+
+    let w = this.bound
+    for (const b of blacklist) {
+      if (b < this.bound) {
+        while (black.has(w)) w++
+
+        this.b2w.set(b, w)
+        w++
+      }
+    }
+  }
+
+  pick(): number {
+    const x = Math.floor(Math.random() * this.bound)
+    return this.b2w.get(x) || x
+  }
+}