146 LRU Cache

使用OrderedDict类实现， 使用 move_to___end 方法，对于LRU Cache进行模拟

class LRUCache(object):

    def __init__(self, capacity):
        """
        :type capacity: int
        """
        self.capacity = capacity
        self.ordered_dict = collections.OrderedDict()


    def get(self, key):
        """
        :type key: int
        :rtype: int
        """
        if key not in self.ordered_dict:
            return -1
        self.ordered_dict.move_to_end(key)
        return self.ordered_dict[key]


    def put(self, key, value):
        """
        :type key: int
        :type value: int
        :rtype: None
        """
        if key in self.ordered_dict:
            self.ordered_dict.move_to_end(key)
        self.ordered_dict[key] = value
        if len(self.ordered_dict) > self.capacity:
            self.ordered_dict.popitem(last =  False

# Your LRUCache object will be instantiated and called as such:
# obj = LRUCache(capacity)
# param_1 = obj.get(key)
# obj.put(key,value)