Submission #746061

#	Time	Username	Problem	Language	Result	Execution time	Memory
746061		vjudge1	Event Hopping (BOI22_events)	C++17	0 / 100	223 ms	10008 KiB

events

#include <bits/stdc++.h>
using namespace std;

struct Event {
	int s, e, idx;
};

int main() {
	ios::sync_with_stdio(0); cin.tie(0);
	int n, q; cin >> n >> q;
	vector<Event> events(n);
	int j = 0;
	for (Event &i : events) {
		cin >> i.s >> i.e;
		i.idx = ++j;
	}
	vector<Event> old = events;
	sort(events.begin(), events.end(), [&](Event a, Event b) {
		if (a.e == b.e) return a.s < b.s;
		return a.e < b.e;
	});
	
	map<int, pair<int, int>> m;
	int segment = 1;
	for (int i = 0; i < n; i++) {
		if (i && (events[i].s > events[i-1].e || events[i-1].e > events[i].e)) segment++;
		m[events[i].idx] = {i, segment};
	}
	while (q--) {
		int a, b; cin >> a >> b;
		if (old[a-1].e == old[b-1].e) {
			cout << 1 << "\n";
			continue;
		}
		if (m[a].second != m[b].second) {
			cout << "impossible\n";
			continue;
		}
		a = m[a].first; b = m[b].first;
		if (a > b) cout << "impossible\n";
		else cout << b-a << "\n";
	}
	return 0;
}
 

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