Submission #1178704

#	Time	Username	Problem	Language	Result	Execution time	Memory
1178704		DeMen100ns	Olympiads (BOI19_olympiads)	C++20	100 / 100	46 ms	1700 KiB

olympiads

/*
Author : DeMen100ns (Vo Khac Trieu)
School: University of Science, VNU-HCM
Aim: 
- International Grandmaster Codeforces (2600) 
- ICPC World Final 2025
*/

#include <bits/stdc++.h>

#define int long long

using namespace std;

const long long INF = numeric_limits<long long>::max() / 2;
const int INF_int = 1e9 + 7;

struct State{
    int val, forced;
    vector <int> v;
    vector <bool> ban;

    State(vector <int> v, vector<bool> ban, int forced, vector <vector<int>> &a, int k)
    : v(v), ban(ban), forced(forced){
        vector <int> ans(k, 0);
        for(int i = 0; i < k; ++i){
            for(int j = 0; j < k; ++j){
                ans[i] = max(ans[i], a[v[j]][i]);
            }
        }
        val = accumulate(ans.begin(), ans.end(), 0);
    }

    bool operator <(const State &a) const{
        return val < a.val;
    }
};

void solve(){
    int n, k, c; cin >> n >> k >> c;
    vector <vector<int>> a(n, vector<int>(k, 0));

    for(int i = 0; i < n; ++i){
        for(int j = 0; j < k; ++j) cin >> a[i][j];
    }

    vector <int> opt;
    vector <bool> choose(n, 0);
    for(int i = 0; i < k; ++i){
        int ma = -1, ma_id = -1;
        for(int j = 0; j < n; ++j){
            bool valid = true;
            for(int id : opt) valid &= j != id;
            if (valid && a[j][i] > ma){
                ma = a[j][i];
                ma_id = j;
            }
        }
        opt.push_back(ma_id);
    }

    priority_queue<State, vector<State>> pq;
    pq.push(State(opt, vector<bool>(n, 0), 0, a, k));

    while (c--){
        State u = pq.top(); pq.pop();

        // cerr << "---" << endl << u.val << endl;
        // for(int i : u.v) cerr << i << " "; cerr << endl;

        if (c == 0){
            cout << u.val << endl;
            return;
        }

        vector <bool> nban = u.ban;

        for(int id = u.forced; id < k; ++id){
            nban[u.v[id]] = true;

            vector <int> opt;
            if (id > 0) opt = {u.v.begin(), u.v.begin() + id};

            for(int event = id; event < k; ++event){
                int ma = -1, ma_id = -1;
                for(int i = 0; i < n; ++i){
                    bool valid = !nban[i];
                    for(int j : opt) valid &= i != j;
                    if (valid && a[i][event] > ma){
                        ma = a[i][event];
                        ma_id = i;
                    }
                }
                if (ma_id != -1) opt.push_back(ma_id);
                else break;
            }

            // cerr << id << ": \n";
            // for(int i : opt) cerr << i << " "; cerr << '\n';

            if (opt.size() == k){
                pq.push(State(opt, nban, id, a, k));
            }
        }

        assert(!pq.empty());

       // cerr << pq.size() << endl;
    }
}

signed main(){
    ios_base::sync_with_stdio(0); cin.tie(0);

    int t = 1; // cin >> t;
    for(int test = 1; test <= t; ++test){
        solve();
    }
}

• Subtask 1: 13 / 13
• Subtask 2: 31 / 31
• Subtask 3: 24 / 24
• Subtask 4: 32 / 32