Submission #714221

#	Time	Username	Problem	Language	Result	Execution time	Memory
714221		vjudge1	Event Hopping (BOI22_events)	C++17	10 / 100	1581 ms	128404 KiB

events

#include <bits/stdc++.h>
using namespace std;
vector<vector<int>>g;
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, q;
    cin >> n >> q;
    g.resize(n + 1);
    vector<pair<int, int>>events(n + 1);
    for(int i = 1;i <= n;++i){
        cin >> events[i].first >> events[i].second;
    }
    for(int i = 1;i <= n;++i){
        for(int j = 1;j <= n;++j){
            if(i == j)continue;
            if(events[i].second >= events[j].first && events[i].second <= events[j].second){
                g[i].push_back(j);
            }
        }
    }
//    for(int i = 1;i <= n;++i){
//        cout << i << ": ";
//        for(int j : g[i]){
//            cout << j << " ";
//        }
//        cout << '\n';
//    }
    vector<vector<int>>dist(n + 1, vector<int>(n + 1, -1));
    for(int i = 1;i <= n;++i){
        dist[i][i] = 0;
        queue<int>q;
        q.push(i);
        while(!q.empty()){
            int cur = q.front();
            q.pop();
            for(int v : g[cur]){
                if(dist[i][v] == -1){
                    dist[i][v] = dist[i][cur] + 1;
                    q.push(v);
                }
            }
        }
    }
    while(q--){
        int u, v;
        cin >> u >> v;
        if(dist[u][v] == -1)cout << "impossible\n";
        else cout << dist[u][v] << '\n';
    }
}

• Subtask 1: 0 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30