Hash Tables

class HashTable<V> {
  private buckets: Array<Array<[string, V]>>;
  private size: number;

  constructor(size = 53) {
    this.size = size;
    this.buckets = Array.from({ length: size }, () => []);
  }

  private hash(key: string): number {
    let total = 0;
    for (let i = 0; i < key.length; i++) {
      total = (total * 31 + key.charCodeAt(i)) % this.size;
    }
    return total;
  }

  set(key: string, value: V): void {
    const index = this.hash(key);
    const bucket = this.buckets[index];
    const existing = bucket.find(([k]) => k === key);
    if (existing) existing[1] = value;
    else bucket.push([key, value]);
  }

  get(key: string): V | undefined {
    const index = this.hash(key);
    const pair = this.buckets[index].find(([k]) => k === key);
    return pair?.[1];
  }
}