oj.uz

Submission #775389

# Submission time Handle Problem Language Result Execution time Memory
775389 2023-07-06T10:45:06 Z penguin133 Event Hopping (BOI22_events) C++17
30 / 100
 140 ms 24908 KB 
#include <bits/stdc++.h>
using namespace std;

#define int long long
#define pi pair<int, int>
#define pii pair<int, pi>
#define fi first
#define se second
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

int par[20][200005], n, q, S[200005], E[200005];
pi A[200005], B[200005];

void solve(){
	cin >> n >> q;
	for(int i=1;i<=n;i++){
		cin >> S[i] >> E[i];
		A[i] = {S[i], i};
		B[i] = {E[i], i};
	}
	sort(A+1, A+n+1);
	sort(B+1, B+n+1);
	int in = 1, mx = 0, idx = -1;
	for(int i=1;i<=n;i++){
		while(in <= n && A[in].fi <= B[i].fi){
			if(mx < E[A[in].se])mx = E[A[in].se], idx = A[in].se;
			in++;
		}
		if(mx > B[i].fi)par[0][B[i].se] = idx;
	}
	for(int i=1;i<=19;i++)for(int j=1;j<=n;j++)par[i][j] = par[i-1][par[i-1][j]];
	while(q--){
		int s, e; cin >> s >> e;
		if(E[s] > E[e])cout << "impossible\n";
		else if(s == e)cout << 0 << '\n';
		else if(S[e] <= E[s] && E[s] <= E[e])cout << 1 << '\n';
		else{
			int ans = 0, cur = s;
			for(int i=19;i>=0;i--){
				int x = par[i][cur];
				if(x == 0)continue;
				if(E[x] < S[e])cur = par[i][cur], ans += (1 << i);
			}
			if(par[0][cur] == 0){
				cout << "impossible\n";
				continue;
			}
			cur = par[0][cur];
			ans+=2;
			if(S[e] <= E[cur] && E[cur] <= E[e])cout << ans << '\n';
			else cout << "impossible\n";
		}
	}
}

main(){
	ios::sync_with_stdio(0);cin.tie(0);
	int tc = 1;
	//cin >> tc;
	for(int tc1=1;tc1<=tc;tc1++){
		// cout << "Case #" << tc1 << ": ";
		solve();
	}
}

Compilation message

events.cpp:59:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   59 | main(){
      | ^~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 61 ms 24464 KB Output is correct
3 Correct 83 ms 24404 KB Output is correct
4 Correct 140 ms 24476 KB Output is correct
5 Correct 89 ms 24484 KB Output is correct
6 Correct 80 ms 24560 KB Output is correct
7 Correct 81 ms 24596 KB Output is correct
8 Correct 70 ms 24908 KB Output is correct
9 Correct 65 ms 24148 KB Output is correct
10 Correct 89 ms 24856 KB Output is correct
11 Correct 93 ms 24856 KB Output is correct
12 Correct 42 ms 23388 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 1 ms 724 KB Output is correct
4 Correct 1 ms 692 KB Output is correct
5 Incorrect 1 ms 596 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 1 ms 724 KB Output is correct
4 Correct 1 ms 692 KB Output is correct
5 Incorrect 1 ms 596 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 1 ms 724 KB Output is correct
4 Correct 1 ms 692 KB Output is correct
5 Incorrect 1 ms 596 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 64 ms 24452 KB Output is correct
2 Correct 91 ms 24436 KB Output is correct
3 Correct 122 ms 24400 KB Output is correct
4 Correct 64 ms 24144 KB Output is correct
5 Correct 98 ms 24848 KB Output is correct
6 Correct 83 ms 24648 KB Output is correct
7 Correct 80 ms 24608 KB Output is correct
8 Correct 73 ms 24748 KB Output is correct
9 Correct 37 ms 22716 KB Output is correct
10 Correct 85 ms 24164 KB Output is correct
11 Correct 69 ms 23996 KB Output is correct
12 Correct 77 ms 24204 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 61 ms 24464 KB Output is correct
3 Correct 83 ms 24404 KB Output is correct
4 Correct 140 ms 24476 KB Output is correct
5 Correct 89 ms 24484 KB Output is correct
6 Correct 80 ms 24560 KB Output is correct
7 Correct 81 ms 24596 KB Output is correct
8 Correct 70 ms 24908 KB Output is correct
9 Correct 65 ms 24148 KB Output is correct
10 Correct 89 ms 24856 KB Output is correct
11 Correct 93 ms 24856 KB Output is correct
12 Correct 42 ms 23388 KB Output is correct
13 Correct 1 ms 468 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 724 KB Output is correct
16 Correct 1 ms 692 KB Output is correct
17 Incorrect 1 ms 596 KB Output isn't correct
18 Halted 0 ms 0 KB -