LRU cache

class LRUCache{
public:
 
    //map<int,int> v;
    vector<int> v;
    map<int,int> m;
    int s;
    LRUCache(int capacity) {
        s=capacity;
    }
     void adjust(int key){
        int idx = -1;
        //for(int i = 0; i <= v.size() - 1; i ++)
            for(int i = v.size()-1; i >=0; i --)            //必须是倒序的，正序的不可以
            if(v[i] == key){
                idx = i;
                break;
            }
        v.erase(v.begin() + idx);
        v.push_back(key);
        
            /*std::vector<int>::iterator it = v.end();
            while(it!=v.begin()){
                it--;
                if(*it == key)
                    {v.erase(it); v.push_back(key); break;}
            }*/
    
    }
    
    
    int get(int key) {
        /*if(!m.count(key)) 
             return -1;*/                           //艾玛这个起了解决超时问题的决定性作用
        if(m.find(key) == m.end()){
            return -1;
        }
        else{
        
            /*std::vector<int>::iterator it = v.begin();
            while(it<v.end()){
                if(*it == key)
                    {    v.erase(it); break;} 
                it++;
            }
            v.push_back(key);*/
            adjust(key);
            return m[key];
            //v.insert(pair<int,int>(key,v.size()));
        }
       
    }
    
    void set(int key, int value) {
        if(m.count(key)) {    //如果更新改key的值
            m[key] = value;
            /*std::vector<int>::iterator it = v.begin();
            while(it<v.end()){
                if(*it == key)
                       {    v.erase(it); break;} 
                it++;
            } v.push_back(key);*/
            
            adjust(key);
         
        return;
            
        }
        else if(v.size() < s){    //插入新值，并且队列未满
             m[key] = value;
             v.push_back(key);
            return;
    }
    else {//插入新值，并且队列已满
           // m.insert(pair<int,int>(key,value));
        
            m.erase(v[0]);    //这里可以直接用元素来删除，不一定非要用iterator  
            m[key] = value;
            v.erase(v.begin());
            v.push_back(key);
            return;
    }
    

        
    }
};