Method pushRight

javascript/0460-lfu-cache.js:44–50

(val)

    }

    pushRight(val) {
        let newNode = new ListNode(val, this.Right);
        newNode.prev = this.Right.prev;
        newNode.prev.next = newNode;
        this.Right.prev = newNode;
        this.map.set(val, newNode);
    }

    update(val) {
        this.pop(val);