146.lru-缓存.ts

/*
 * @lc app=leetcode.cn id=146 lang=typescript
 *
 * [146] LRU 缓存
 */

// @lc code=start
class LRUCache {
  private capacity: number;
  private cache: Map<number, number>;
  constructor(capacity: number) {
    this.capacity = capacity;
    this.cache = new Map<number, number>();
  }

  get(key: number): number {
    if (this.cache.has(key)) {
      const value = this.cache.get(key);
      this.cache.delete(key);
      this.cache.set(key, value!);
      return value!;
    } else {
      return -1;
    }
  }

  put(key: number, value: number): void {
    if (this.cache.has(key)) {
      this.cache.delete(key);
      this.cache.set(key, value);
    } else {
      if (this.cache.size >= this.capacity) {
        // 用这种方法去删除第一个
        for (const [key, value] of this.cache) {
          this.cache.delete(key);
          break;
        }
      }
      this.cache.set(key, value);
    }
  }
}

/**
 * Your LRUCache object will be instantiated and called as such:
 * var obj = new LRUCache(capacity)
 * var param_1 = obj.get(key)
 * obj.put(key,value)
 */
// @lc code=end