【面试准备】letcode—LRU

#include <iostream>
#include <map>
#include <list>
using namespace std;

struct CacheNode{
	int key;
	int value;
	CacheNode(int x,int y):key(x),value(y){}
};

class LRUCache{
public:
	LRUCache(int capacity){
		size = capacity;
	}
	
	int get(int key){
		if(cacheMap.find(key) != cacheMap.end()){
			auto it = cacheMap[key];
			cacheList.splice(cacheList.begin(),cacheList,it);
			cacheMap[key] = cacheList.begin();
			return cacheList.begin()->value;
		}
		else{
			return -1;
		}
	}
	
	void set(int key,int value){
		if(cacheMap.find(key) == cacheMap.end()){
			if(cacheList.size() == size){
				cacheMap.erase(cacheList.back().key);
				cacheList.pop_back();
			}
			cacheList.push_front(CacheNode(key,value));
			cacheMap[key] = cacheList.begin();
		}
		else{
			auto it = cacheMap[key];
			cacheList.splice(cacheList.begin(),chacheList,it);
			cacheMap[key] = cacheList.begin();
			cacheList.begin()->value = value;
		}
	}
private:
	int size;
	list<CacheNode> cacheList;
	unordered_map<int,list<CacheNode>::iterator >  cacheMap;
};