chore: add daily leetcode post [146]LRU 缓存_translated

Author: longsizhuo

app/docs/CommunityShare/Leetcode/[146]LRU 缓存_translated.md

@@ -0,0 +1,111 @@
+---
+title: 146.LRU cache
+date: '2024.01.01 0:00'
+tags:
+  - Python
+  - answer
+  - Linked
+  - design
+  - Hash table
+  - 双向Linked
+        
+abbrlink: b9130c0e
+---
+
+# topic：
+I met for the first time：'2023/3/14-15:21'
+
+
+[146.LRU cache.md](https://leetcode-cn.com/problems/lru-cache/)
+
+# Thought：
+Simple simulation，Use the dictionary to make it，好像完全没用到双向Linked和LRU的Thought。。。I'm guilty，I can remember the air conditioner made in half a year ago。
+answer就看Code的注释应该就能看懂，I will reply if I don’t understand。
+
+# Code：
+```python
+class LRUCache:
+
+    def __init__(self, capacity: int):
+        self.capacity = capacity
+        self.cache = collections.OrderedDict()
+
+    def get(self, key: int) -> int:
+        # ifkeyIn the dictionary，returnvalue
+        if key in self.cache:
+            self.cache.move_to_end(key)
+            return self.cache[key]
+
+        else:
+            # ifkey不In the dictionary，return-1
+            return -1
+
+    def put(self, key: int, value: int) -> None:
+        if key in self.cache:
+            # ifkeyIn the dictionary，renewvalue
+            self.cache.move_to_end(key)
+            self.cache[key] = value
+        else:
+            if len(self.cache) == self.capacity:
+                # ifkey不In the dictionary，The dictionary is full，Delete the least recently used elements
+                self.cache.popitem(last=False)
+            # ifkey不In the dictionary，Dictionary is not full，Add element
+            # self.cache.move_to_end(key)
+            self.cache[key] = value
+```
+
+# Second solution
+
+```python
+class Node:
+    # Improve the speed of access attributes，And save memory
+    __slots__ = 'prev', 'next', 'key', 'value'
+
+    def __init__(self, key=0, value=0):
+        self.key = key
+        self.value = value
+
+class LRUCache:
+    def __init__(self, capacity: int):
+        self.capacity = capacity
+        self.dummy = Node()  # Sentry node
+        self.dummy.prev = self.dummy
+        self.dummy.next = self.dummy
+        self.key_to_node = dict()
+
+    def get_node(self, key: int) -> Optional[Node]:
+        if key not in self.key_to_node:  # No this book
+            return None
+        node = self.key_to_node[key]  # Have this book
+        self.remove(node)  # Draw this book
+        self.push_front(node)  # Put on the top
+        return node
+
+    def get(self, key: int) -> int:
+        node = self.get_node(key)
+        return node.value if node else -1
+
+    def put(self, key: int, value: int) -> None:
+        node = self.get_node(key)
+        if node:  # Have this book
+            node.value = value  # renew value
+            return
+        self.key_to_node[key] = node = Node(key, value)  # new book
+        self.push_front(node)  # Put on the top
+        if len(self.key_to_node) > self.capacity:  # There are too many books
+            back_node = self.dummy.prev
+            del self.key_to_node[back_node.key]
+            self.remove(back_node)  # Remove the last book
+
+    # Delete a node（Draw a book）
+    def remove(self, x: Node) -> None:
+        x.prev.next = x.next
+        x.next.prev = x.prev
+
+    # 在Linked头添加一个节点（把一本书Put on the top）
+    def push_front(self, x: Node) -> None:
+        x.prev = self.dummy
+        x.next = self.dummy.next
+        x.prev.next = x
+        x.next.prev = x
+```