oj.uz

Submission #574188

# Submission time Handle Problem Language Result Execution time Memory
574188 2022-06-08T06:59:43 Z 8e7 Event Hopping (BOI22_events) C++17
30 / 100
 170 ms 21824 KB 
//Challenge: Accepted
#include <bits/stdc++.h>
using namespace std;
#ifdef zisk
void debug(){cout << endl;}
template<class T, class ... U> void debug(T a, U ... b){cout << a << " ", debug(b...);}
template<class T> void pary(T l, T r) {
	while (l != r) cout << *l << " ", l++;
	cout << endl;
}
#else
#define debug(...) 0
#define pary(...) 0
#endif
#define ll long long
#define maxn 200005
#define pii pair<int, int>
#define ff first
#define ss second
#define io ios_base::sync_with_stdio(0);cin.tie(0);
const int inf = 1<<30;
pii seg[maxn];
vector<int> ev[maxn];
bool on[maxn];
int to[17][maxn];
int main() {
	io
	int n, q;
	cin >> n >> q;
	{
		vector<int> val;
		for (int i = 1;i <= n;i++) {
			cin >> seg[i].ff >> seg[i].ss;
			val.push_back(seg[i].ff);
			val.push_back(seg[i].ss);
		}
		sort(val.begin(), val.end());
		val.resize(int(unique(val.begin(), val.end()) - val.begin()));
		for (int i = 1;i <= n;i++) {
			seg[i].ff = lower_bound(val.begin(), val.end(), seg[i].ff) - val.begin();
			seg[i].ss = lower_bound(val.begin(), val.end(), seg[i].ss) - val.begin();
			ev[seg[i].ff].push_back(i);
			ev[seg[i].ss].push_back(i);
		}
	}
	seg[0].ss = inf;
	priority_queue<pii, vector<pii>, less<pii> > pq;
	for (int i = 0;i < 2*n;i++) {
		vector<int> tmp;
		for (int j:ev[i]) {
			if (!on[j]) {
				on[j] = 1;
				pq.push({seg[j].ss, j});
			} else {
				tmp.push_back(j);
			}
		}
		while (pq.size() && pq.top().ff <= i) pq.pop();
		for (int j:tmp) {
			to[0][j] = (pq.size() ? pq.top().ss : 0);
		}
	}
	//pary(to[0], to[0] + n + 1);
	for (int i = 1;i < 17;i++) {
		for (int j = 0;j <= n;j++) to[i][j] = to[i-1][to[i-1][j]];
	}
	while (q--) {
		int s, t;
		cin >> s >> t;	
		int ans = -1;
		if (seg[t].ss >= seg[s].ss) {
			if (seg[t].ff <= seg[s].ss) {
				if (s == t) ans = 0;
				else ans = 1;
			} else {
				int cur = s, dis = 0;
				for (int i = 16;i >= 0;i--) {
					if (seg[to[i][cur]].ss < seg[t].ff) {
						cur = to[i][cur];
						dis += 1<<i;
					}
				}
				if (seg[cur].ss >= seg[t].ff) {
					ans = dis + 1;
				} else if (to[0][cur] && seg[to[0][cur]].ss <= seg[t].ss && seg[to[0][cur]].ss >= seg[t].ff) {
					ans = dis + 2;
				} 
			}
		}
		if (ans == -1) cout << "impossible" << "\n";
		else cout << ans << "\n";
	}
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5076 KB Output is correct
2 Correct 116 ms 18124 KB Output is correct
3 Correct 144 ms 18080 KB Output is correct
4 Correct 157 ms 18108 KB Output is correct
5 Correct 138 ms 18532 KB Output is correct
6 Correct 131 ms 18804 KB Output is correct
7 Correct 145 ms 18936 KB Output is correct
8 Correct 126 ms 21824 KB Output is correct
9 Correct 122 ms 20044 KB Output is correct
10 Correct 157 ms 17732 KB Output is correct
11 Correct 138 ms 18824 KB Output is correct
12 Correct 69 ms 16856 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5076 KB Output is correct
2 Correct 2 ms 5076 KB Output is correct
3 Correct 4 ms 5192 KB Output is correct
4 Correct 5 ms 5204 KB Output is correct
5 Incorrect 3 ms 5204 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5076 KB Output is correct
2 Correct 2 ms 5076 KB Output is correct
3 Correct 4 ms 5192 KB Output is correct
4 Correct 5 ms 5204 KB Output is correct
5 Incorrect 3 ms 5204 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5076 KB Output is correct
2 Correct 2 ms 5076 KB Output is correct
3 Correct 4 ms 5192 KB Output is correct
4 Correct 5 ms 5204 KB Output is correct
5 Incorrect 3 ms 5204 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 121 ms 18084 KB Output is correct
2 Correct 127 ms 18060 KB Output is correct
3 Correct 170 ms 18116 KB Output is correct
4 Correct 131 ms 20004 KB Output is correct
5 Correct 137 ms 17572 KB Output is correct
6 Correct 156 ms 21376 KB Output is correct
7 Correct 146 ms 21436 KB Output is correct
8 Correct 140 ms 21396 KB Output is correct
9 Correct 129 ms 20640 KB Output is correct
10 Correct 141 ms 21000 KB Output is correct
11 Correct 145 ms 20912 KB Output is correct
12 Correct 153 ms 21080 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5076 KB Output is correct
2 Correct 116 ms 18124 KB Output is correct
3 Correct 144 ms 18080 KB Output is correct
4 Correct 157 ms 18108 KB Output is correct
5 Correct 138 ms 18532 KB Output is correct
6 Correct 131 ms 18804 KB Output is correct
7 Correct 145 ms 18936 KB Output is correct
8 Correct 126 ms 21824 KB Output is correct
9 Correct 122 ms 20044 KB Output is correct
10 Correct 157 ms 17732 KB Output is correct
11 Correct 138 ms 18824 KB Output is correct
12 Correct 69 ms 16856 KB Output is correct
13 Correct 3 ms 5076 KB Output is correct
14 Correct 2 ms 5076 KB Output is correct
15 Correct 4 ms 5192 KB Output is correct
16 Correct 5 ms 5204 KB Output is correct
17 Incorrect 3 ms 5204 KB Output isn't correct
18 Halted 0 ms 0 KB -