51 lines
1.2 KiB
C++
51 lines
1.2 KiB
C++
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#ifndef S0146_LRU_CACHE_HPP
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#define S0146_LRU_CACHE_HPP
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#include <cstdlib>
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#include <unordered_map>
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class LRUCache {
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public:
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/**
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* @brief Least Recently Used Cache
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*
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* 这是一种常用的页面置换算法，选择最近最久未使用的页面予以淘汰
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*
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* @param capacity 容量，这是一个正整数
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*/
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LRUCache(int capacity);
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/**
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* @brief 读取数据
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*
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* @param key 数据对应的键值
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* @return 数据的值
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*/
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int get(int key);
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/**
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* @brief 放入对应的数据
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*
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* @param key 数据对应的键值
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* @param value 数据对应的值
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*/
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void put(int key, int value);
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private:
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struct CacheNode {
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int key;
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int value;
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CacheNode *next;
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CacheNode *prev;
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CacheNode(int key, int value)
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: key(key), value(value), next(nullptr), prev(nullptr){};
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CacheNode(int key, int value, CacheNode *next, CacheNode *prev)
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: key(key), value(value), next(next), prev(prev){};
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};
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CacheNode *head;
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CacheNode *tail;
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int capacity;
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std::unordered_map<int, CacheNode *> map; // 键值是 key，值是该节点的指针
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void moveToHead(CacheNode *node); // 将节点移动到头部
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};
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#endif
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