Submission #637871

#	Time	Username	Problem	Language	Result	Execution time	Memory
637871		kideso	Fountain (eJOI20_fountain)	C++17	60 / 100	1566 ms	256756 KiB

fountain

#include <iostream>
#include <queue>
#include <algorithm>

using namespace std;

struct P1{
    int start, extra;
};

struct P{
    int volume, index;
};

vector<vector<P> > routes(1, vector<P> ());
int N, Q, v, d;

bool operator < (const P &a, int val){
    return a.volume < val;
}

int main(){
    cin >> N >> Q;
    vector<P1> x(N + 1, {0, 0});
    vector<int> diameters(N + 1, 0);

    cin >> diameters[1] >> v;

    x[1] = {1, 0};
    routes.push_back(vector<P>());
    routes[1].push_back({v, 1});

    for(int i = 2; i <= N; ++i){
        cin >> diameters[i] >> v;
        bool ok = false;

        for(int j = 1; j < routes.size(); ++j){
            auto [V, s] = routes[j].back();
            if(diameters[s] < diameters[i]){
                ok = true;
                if(x[i].start == 0)
                    x[i] = {j, V};

                V += v;
                routes[j].push_back({V, i});
            }
        }

        if(!ok){
            int p = routes.size();
            x[i] = {p, 0};
            routes.push_back(vector<P>(1, {v, i}));
        }
    }

    int from, volume;
    while(Q--){
        cin >> from >> volume;
        volume += x[from].extra;
        from = x[from].start;
        auto it = lower_bound(routes[from].begin(), routes[from].end(), volume);
        cout << (it == routes[from].end() ? 0 : it -> index) << '\n';
    }

    return 0;
}

Compilation message (stderr)

fountain.cpp: In function 'int main()':
fountain.cpp:37:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<P> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |         for(int j = 1; j < routes.size(); ++j){
      |                        ~~^~~~~~~~~~~~~~~

• Subtask 1: 30 / 30
• Subtask 2: 30 / 30
• Subtask 3: 0 / 40