LRU 缓存 · 实现

from collections import OrderedDict

class LRU:
    def __init__(____):
        self.k = k
        self.d = OrderedDict()
    def put(____):
        if key in self.d:
            self.d.move_to_end(____)
        self.d[key] = ____
        if len(____) > self.k:
            self.d.popitem(____)

def solve():
    lru = LRU(____)
    lru.put(____)
    lru.put(____)
    lru.put(____)
    return '____'.join(lru.d.keys())