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[fix][javascript] design-twitter #1588

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[fix][javascript] design-twitter #1588

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92 changes: 9 additions & 83 deletions 多语言解法代码/solution_code.md
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Original file line number Diff line number Diff line change
Expand Up @@ -19037,26 +19037,28 @@ var Twitter = function() {
const followedUserSet = user.followedUserSet;
// 每个用户的 tweet 是一条按时间排序的链表
// 现在执行合并多条有序链表的逻辑，找出时间线中的最近 10 条动态
const pq = new PriorityQueue((a, b) => {
// 按照每条 tweet 的发布时间降序排序（最近发布的排在事件流前面）
return b.timestamp - a.timestamp;
const pq = new PriorityQueue({
compare: (a, b) => {
// 按照每条 tweet 的发布时间降序排序（最近发布的排在事件流前面）
return b.timestamp - a.timestamp;
}
});
// 该用户自己的 tweet 也在时间线内
if (user.tweetHead !== null) {
pq.offer(user.tweetHead);
pq.enqueue(user.tweetHead);
}
for (const other of followedUserSet) {
if (other.tweetHead !== null) {
pq.offer(other.tweetHead);
pq.enqueue(other.tweetHead);
}
}
// 合并多条有序链表
let count = 0;
while (!pq.isEmpty() && count < 10) {
const tweet = pq.poll();
const tweet = pq.dequeue();
res.push(tweet.id);
if (tweet.next !== null) {
pq.offer(tweet.next);
pq.enqueue(tweet.next);
}
count++;
}
Expand Down Expand Up @@ -19088,82 +19090,6 @@ var Twitter = function() {
follower.unfollow(followee);
};
};

// 优先队列实现
class PriorityQueue {
constructor(comparator) {
this.heap = [];
this.comparator = comparator;
}

/**
* 上浮操作
* @param {number} index - 上浮节点的下标
*/
swim(index) {
let currentIndex = index;
while (currentIndex > 0) {
const parentIndex = Math.floor((currentIndex - 1) / 2);
if (this.comparator(this.heap[currentIndex], this.heap[parentIndex]) >= 0) {
break;
}
[this.heap[currentIndex], this.heap[parentIndex]] = [this.heap[parentIndex], this.heap[currentIndex]];
currentIndex = parentIndex;
}
}

/**
* 下沉操作
* @param {number} index - 下沉节点的下标
*/
sink(index) {
let currentIndex = index;
while (currentIndex * 2 + 1 < this.heap.length) {
const leftIndex = currentIndex * 2 + 1;
const rightIndex = currentIndex * 2 + 2 < this.heap.length ? currentIndex * 2 + 2 : leftIndex;
const smallerIndex = this.comparator(this.heap[leftIndex], this.heap[rightIndex]) <= 0 ? leftIndex : rightIndex;
if (this.comparator(this.heap[currentIndex], this.heap[smallerIndex]) <= 0) {
break;
}
[this.heap[currentIndex], this.heap[smallerIndex]] = [this.heap[smallerIndex], this.heap[currentIndex]];
currentIndex = smallerIndex;
}
}

/**
* 插入元素
* @param {*} value - 插入的值
*/
offer(value) {
this.heap.push(value);
this.swim(this.heap.length - 1);
}

/**
* 弹出堆顶元素
* @return {*} 堆顶元素
*/
poll() {
if (this.size() === 0) {
return null;
}
if (this.size() === 1) {
return this.heap.pop();
}
const top = this.heap[0];
this.heap[0] = this.heap.pop();
this.sink(0);
return top;
}

/**
* 获取堆大小
* @return {number} 堆大小
*/
size() {
return this.heap.length;
}
}
```

```python
Expand Down