Submission #857680

#	Time	Username	Problem	Language	Result	Execution time	Memory
857680		vgtcross	Event Hopping (BOI22_events)	C++17	10 / 100	1588 ms	3156 KiB

events

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using pii = pair<int, int>;

void solve() {
    int n, q;
    cin >> n >> q;
    
    vector<pii> v(n);
    for (pii &p : v) cin >> p.first >> p.second;
    
    while (q--) {
        int a, b;
        cin >> a >> b;
        --a;--b;
        
        queue<pii> bfs;
        bfs.push({a, 0});
        int ans = -1;
        vector<bool> vis(n, 0);
        vis[a] = 1;
        while (bfs.size()) {
            pii p = bfs.front();
            bfs.pop();
            if (p.first == b) {
                ans = p.second;
                break;
            }
            for (int i = 0; i < n; ++i) if (!vis[i] && v[i].first <= v[p.first].second && v[p.first].second <= v[i].second) {
                vis[i] = 1;
                bfs.push({i, p.second+1});
            }
        }
        
        cout << (ans == -1 ? "impossible" : to_string(ans)) << '\n';
    }
}

int main() {
    cin.tie(0) -> sync_with_stdio(0);
    
    solve();
}

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