class Node:
def __init__(self, key=0, value=0):
self.key = key
self.value = value
self.prev = None
self.next = None
class LRUCache:
def __init__(self, capacity: int):
self.capacity = capacity
self.length = 0
self.map = {}
self.head = Node()
self.tail = Node()
self.head.next = self.tail
self.tail.prev = self.head
def get(self, key: int) -> int:
if key in self.map:
self.remove(self.map[key])
self.refresh(self.map[key])
return self.map[key].value
else:
return -1
def put(self, key: int, value: int) -> None:
if key in self.map:
self.map[key].value = value
self.remove(self.map[key])
self.refresh(self.map[key])
else:
if self.length == self.capacity:
t = self.head.next.key
self.remove(self.head.next)
del self.map[t]
node = Node(key, value)
self.refresh(node)
self.map[key] = node
else:
node = Node(key, value)
self.refresh(node)
self.map[key] = node
self.length += 1
def remove(self, node):
node.next.prev = node.prev
node.prev.next = node.next
def refresh(self, node):
node.prev = self.tail.prev
self.tail.prev.next = node
node.next = self.tail
self.tail.prev = node
def show(self):
cur = self.head.next
while cur.next:
print(cur.key,cur.value, end="|")
cur = cur.next
print()
# Your LRUCache object will be instantiated and called as such:
# obj = LRUCache(capacity)
# param_1 = obj.get(key)
# obj.put(key,value)