ccf-201909-4 推荐系统

中等的模拟题，自己写的太搓了。

1. 自己原来写了离散化，后来删了
2. 原来超时，后来加了一个很小的优化

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
#include<queue>
#include<cmath>
#include<map>
#include<stack>
#include<set>
#include<bitset>
#include<unordered_map>

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
#define pb(x) push_back(x)
#define cls(x, val) memset(x, val, sizeof(x))
#define fi first
#define se second
#define mp(x, y) make_pair(x, y)
#define inc(i, l, r) for(int i=l; i<=r; i++)
const int inf = 0x3f3f3f3f;
const int maxn = 3e5+10;
int a[maxn];
int price[200000];
unordered_map<int, int> mp;
int m, n;
int col;

int b[maxn];
int op_num;

struct Node{
    int id;
    int price;
    int type;
    bool operator < (const Node &b) const {
        if(price!=b.price) return price>b.price;
        else if(type != b.type) return type<b.type;
        return id<b.id;

    }
};

set<Node> st[55];
int k[60];

void add(int type, int commodity, int score){
    st[type].insert(Node{commodity, score, type});
}

void del(int type, int commodity){
    if(st[type].count(Node{commodity, mp[commodity], type})!=0)
        st[type].erase(Node{commodity, mp[commodity], type});

}

void process(int lim, int type){
    if(st[type].empty()){
        cout<<-1<<"
";
        return ;
    }
    set<Node>::iterator it = st[type].begin();
    for(; it!=st[type].end(); it++){
        lim--;
        if(lim==0){
            cout<<it->id<<"
";
            break;
        }
        else {
            cout<<it->id<<" ";
        }
    }
}



int main(){
    ios::sync_with_stdio(false);
    cin>>m>>n;
    for(int i=1; i<=n; i++){
        cin>>a[i]>>price[i];
        mp[a[i]] = price[i];
    }

    for(int i=0; i<m; i++){
        for(int j=1; j<=n; j++){
            st[i].insert(Node{a[j], price[j], i});
        }
    }
    cin>>op_num;
    int op, type, commodity, score;

    for(int i=1; i<=op_num; i++){
        cin>>op;
        if(op == 1){
            cin>>type>>commodity>>score;
            mp[commodity] = score;
            add(type, commodity, score);
        }
        else if(op == 2){
            cin>>type>>commodity;
            del(type, commodity);
        }
        else{
            int K;
            cin>>K;
            int tot = 0;
            for(int j=0; j<m; j++) cin>>k[j], tot += k[j];
            if(K>=tot)
                for(int j=0; j<m; j++){
                    process(k[j], j);
                }
            else{
                vector<Node> pq;
                pq.clear();
                set<Node>::iterator it;
                for(int j=0; j<m; j++){
                    int cnt = 0;
                    for(it=st[j].begin(); it!=st[j].end()&&cnt<min(K, k[j]); it++){
                        pq.push_back(*it);
                        cnt++;
                    }
                }
//                cout<<"--------------"<<endl;
//                for(int j=0; j<pq.size(); j++){
//                    cout<<pq[j].id<<endl;
//                }
//                cout<<"---------------"<<endl;
                sort(pq.begin(), pq.end());
                vector<int> ans[60];
                for(int j=0; j<60; j++) ans[j].clear();
                for(int j=0; j<K; j++){
                    int cnt = 0;
                    for(int s=0; s<m; s++){
                        if(st[s].count(pq[j])!=0){
                            ans[s].push_back(pq[j].id);
                        }
                    }
                }
                for(int j=0; j<m; j++){
                    if(ans[j].size() == 0){
                        cout<<-1<<"
";
                    }
                    else{
                        int sz =  ans[j].size();
                        for(int s=0; s<sz-1; s++) cout<<ans[j][s]<<" ";
                        cout<<ans[j][sz-1]<<"
";
                    }
                }
            }
        }
    }


    return 0;
}
/*
2 3
1 3
2 2
3 1
8
3 100 1 1
1 0 4 3
1 0 5 1
3 10 2 2
3 10 1 1
2 0 1
3 2 1 1
3 1 1 1
*/