typescript lru

lru.ts

class lru {
  size: number;
  n: number;
  key2val: Map<string, any>;
  keys: string[];
  
  constructor(size: number) {
    this.size = size;
    this.n = 0;
    this.key2val = new Map<string,any>();
    this.keys = Array<string>(size).fill("");
  }
  
  get(key: string) {
    if (this.key2val.has(key)) {
      let val = this.key2val.get(key);
      this.set(key, val);
      return val;
    } else {
      return undefined;
    }
  }
  
  set(key: string, val: any) {
    let found: boolean = false;
    this.keys = this.keys.filter(function f(element, index, array) {
      if (element === key) {
        found = true;
        return false;
      } else {
        return true;
      }
    });

    if (!found) {
      const rm = this.keys.pop();
      if ((typeof rm === "string") && (rm !== "")) {
        this.key2val.delete(rm);
      }
    }
    this.keys.unshift(key);
    this.key2val.set(key, val);
  }

  print(): void {
    console.log(`keys: ${this.keys}`);
  }
}

let l = new lru(3);
l.print();
l.set('a',1);
l.print();
l.set('b',2);
l.print();
l.set('c',3);
l.print();
console.log(l.get('a'));
l.print();
l.set('d',4);
l.print();
console.log(l.get('b'));