#include<iostream>
#include<string>
#include<algorithm>
#include<bits/stdc++.h>
using namespace std;
struct Node{
    string name;
    int views;
    string category;
    Node *left,*right; 
    Node(string _name,int _views,string _category):name(_name),views(_views),category(_category),left(NULL),right(NULL){}
}*L,*R;

unordered_map<string,Node*>ha;

void insert(Node* p)//左边是后面
{
    p->right=L->right;
    p->left=L;
    L->right->left=p;
    L->right=p;
}

void remove(Node *p)
{
    p->left->right=p->right;
    p->right->left=p->left;
}

void StreamerOnline(string a,string b, string c)
{
    int cnt=stoi(b);
    auto p=new Node(a,cnt,c);
    insert(p);
    ha[a]=p;
}


int main()
{
    vector<string>streamerInformation={"Ninja", "100000", "Fortnite", "Pokimane", "40000", "Valorant"};
    //vector<string>commands={"StreamerOnline","AOC","75000","Just Chatting","UpdateViews","Ninja","120000","Fortnite","UpdateCategory","Ninja","Fortnite","Warzone","StreamOffline","Ninja","Fortnite","ViewsInCategory","Fortnite","TopStreamInCategory","Valorant","TopStreamer"};
    // vector<string>commands={"StreamerOnline","Bugha","75000","Fortnite","StreamerOnline","Tenzo","30000","Valorant","ViewsInCategory","Fortnite","TopStreamInCategory","Valorant"};
    vector<string>commands={"UpdateViews", "Ninja", "120000", "Fortnite", "ViewsInCategory", "Fortnite"};
    L=new Node("",-1,"");
    R=new Node("",-1,"");
    L->right=R;
    R->left=L;
    for(int i=0;i<streamerInformation.size();i++)
    {
        StreamerOnline(streamerInformation[i],streamerInformation[i+1],streamerInformation[i+2]);
        i+=2;
    }

    for(int i=0;i<commands.size();i++)
    {
        string op=commands[i];
        if(op=="StreamerOnline")
        {
            string a=commands[i+1];
            string b=commands[i+2];
            string c=commands[i+3];
            StreamerOnline(a,b,c);
            i+=3;
            // for(auto p=R->left;p!=L;p=p->left)
            // {
            //     cout<<p->name<<","<<p->views<<","<<p->category<<",";
            // }
        }
        else if(op=="UpdateViews")
        {
            string a=commands[i+1];
            string b=commands[i+2];
            string c=commands[i+3];
            if(!ha.count(a)) continue;
            auto p=ha[a];
            if(p->category!=c) continue;
            p->views=stoi(b);
            i+=3;
            // for(auto p=R->left;p!=L;p=p->left)
            // {
            //     cout<<p->name<<","<<p->views<<","<<p->category<<",";
            // }
        }
        else if(op=="UpdateCategory")
        {
            string a=commands[i+1];
            string b=commands[i+2];
            string c=commands[i+3];
            if(!ha.count(a)) continue;
            auto p=ha[a];
            if(p->category!=b) continue;
            p->category=c;
            i+=3;
            // for(auto p=R->left;p!=L;p=p->left)
            // {
            //     cout<<p->name<<","<<p->views<<","<<p->category<<",";
            // }
        }
        else if(op=="StreamOffline")
        {
            string a=commands[i+1];
            string b=commands[i+2];
            if(!ha.count(a)) continue;
            auto p=ha[a];
            if(p->category!=b) continue;
            remove(p);
            ha.erase(a);
            i+=2;
            // for(auto p=R->left;p!=L;p=p->left)
            // {
            //     cout<<p->name<<","<<p->views<<","<<p->category<<",";
            // }
        }
        else if(op=="ViewsInCategory")
        {
            string a=commands[i+1];
            int res=0;
            for(auto p=L;p!=R;p=p->right)
            {
                if(p->category==a)
                    res+=p->views;
            }
            cout<<res<<endl;
            i+=1;
        }
        else if(op=="TopStreamInCategory")
        {
            string a=commands[i+1];
            bool hascat=false;
            string res;
            int sum=0;
            for(auto p=L;p!=R;p=p->right)
            {
                if(p->category==a)
                {
                    hascat=true;
                    if(p->views>sum)
                    {
                        sum=p->views;
                        res=p->name;
                    }
                }
            }
            if(!hascat || sum==0) cout<<"null";
            else cout<<res;
            i+=1;
        }
        else if(op=="TopStreamer")
        {
            bool has_stream=false;
            string res;
            int sum=0;
            for(auto p=L;p!=R;p=p->right)
            {
                if(p->views>sum)
                {
                    sum=p->views;
                    res=p->name;
                }
            }
            if(!sum) cout<<"null";
            else cout<<res;
            cout<<endl;
        }

    }
    // 双向链表存所有节点，节点存name，views，category
    // hash表存name所在的节点

    // streamerOnline：加入链表尾
    // updateviews: 修改name对应的节点
    // updatecategory: 修改name对应的category
    // streameroffline:删除name对应节点
    // viewsinccategory：直接遍历吧。。
    // topstreamerincategory:直接遍历吧。。
    // topstreamer:直接遍历吧。。
    return 0;
}