复习LRU算法

自己输入测试用例，纯手写实现：

#include
#include
#include
#include
#include
#include
#include
using namespace std;

//Least Recently Used

class LRU {
private:
	int cap;
	list>cache;
	unordered_map>::iterator>map;
public:
	LRU(int cap) {
		this->cap = cap;
	}
	void get(int key) {
		if (map.find(key) != map.end()) {
			auto key_value = *map[key];
			cache.erase(map[key]);
			cache.push_front(key_value);
			map[key] = cache.begin();
			cout << key_value.second << endl;
		}
		else {
			cout << -1 << endl;
		}
		
	}
	void put(int key,int value){
		if (map.find(key) == map.end()) {
			if (cache.size() == cap) {
				map.erase(cache.back().first);
				cache.pop_back();
			}
			cache.push_front({ key,value});
			map[key] = cache.begin();
		}
		else {
			cache.erase(map[key]);
			cache.push_front({ key,value });
			map[key] = cache.begin();
		}
	}
};

int main() {
	LRU* lru = new LRU(3);
	lru->put(1, 1);
	lru->put(2, 2);
	lru->put(3, 3);//<3,3>-><2,2>-><1,1>
	
	lru->get(1);//查询到1后调整链表：<1,1>-><3,3>-><2,2>
	
	lru->put(4, 4);//<4,4>-><1,1>-><3,3>
	
	lru->get(2);//返回-1
}