Submission #714255

#	Time	Username	Problem	Language	Result	Execution time	Memory
714255		vjudge1	Event Hopping (BOI22_events)	C++17	10 / 100	523 ms	12260 KiB

events

#include <bits/stdc++.h>
#define ll long long
#define endl '\n'
using namespace std;
const int MAX = 3e5 + 5;
vector<int> adj[1001];
int color[1001], dis[1001];
void bfs(int s){
    queue<int> q;
    q.push(s);
    dis[s] = 0;
    color[s] = 1;
    while(!q.empty()){
        int u = q.front();
        q.pop();
        for(auto v : adj[u]){
            if(color[v]) continue;
            color[v] = 1;
            dis[v] = dis[u] + 1;
            q.push(v);
        }
    }
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int n, q;
    cin>>n>>q;
    vector<int> S(n + 1), E(n + 1);
    for (int i = 1; i <= n; i++)
    {
        cin>>S[i]>>E[i];
    }
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= n; j++)
        {
            if(S[j] <= E[i] && E[i] <= E[j]) adj[i].push_back(j);
        }
    }
    while(q--){
        memset(color, 0, sizeof(color));
        memset(dis, -1, sizeof(dis));
        int s, e;
        cin>>s>>e;
        bfs(s);
        if(dis[e] != -1) cout<<dis[e]<<endl;
        else cout<<"impossible\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