LFU-кэш

1class LFUCache {
2  private freq = new Map<string, number>()
3  private capacity: number
4 
5  constructor(capacity: number) { this.capacity = capacity }
6 
7  touch(key: string): number {
8    const f = (this.freq.get(key) ?? 0) + 1
9    this.freq.set(key, f)
10    if (this.freq.size > this.capacity) {
11      let least: string | null = null
12      for (const [k, v] of this.freq) {
13        if (least === null || v < (this.freq.get(least) ?? 0)) least = k
14      }
15      this.freq.delete(least!)
16    }
17    return f
18  }
19}