题解 | 设计LRU缓存结构

from collections import OrderedDict


class Solution:
    def __init__(self, capacity):
        self.capacity = capacity
        self.cache = OrderedDict()

    def get(self, key):
        if key not in self.cache:
            return -1
        value = self.cache.pop(key)
        self.cache[key] = value
        return value

    def set(self, key, value):
        if key in self.cache:
            self.cache.pop(key)
        elif len(self.cache) >= self.capacity:
            self.cache.popitem(last=False)
        self.cache[key] = value
        return None