oj.uz

Submission #681993

# Submission time Handle Problem Language Result Execution time Memory
681993 2023-01-15T06:39:00 Z SanguineChameleon Event Hopping (BOI22_events) C++17
20 / 100
 145 ms 17120 KB 
// BEGIN BOILERPLATE CODE

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

#ifdef KAMIRULEZ
	const bool kami_loc = true;
	const long long kami_seed = 69420;
#else
	const bool kami_loc = false;
	const long long kami_seed = chrono::steady_clock::now().time_since_epoch().count();
#endif

const string kami_fi = "kamirulez.inp";
const string kami_fo = "kamirulez.out";
mt19937_64 kami_gen(kami_seed);

long long rand_range(long long rmin, long long rmax) {
	uniform_int_distribution<long long> rdist(rmin, rmax);
	return rdist(kami_gen);
}

long double rand_real(long double rmin, long double rmax) {
	uniform_real_distribution<long double> rdist(rmin, rmax);
	return rdist(kami_gen);
}

void file_io(string fi, string fo) {
	if (fi != "" && (!kami_loc || fi == kami_fi)) {
		freopen(fi.c_str(), "r", stdin);
	}
	if (fo != "" && (!kami_loc || fo == kami_fo)) {
		freopen(fo.c_str(), "w", stdout);
	}
}

void set_up() {
	if (kami_loc) {
		file_io(kami_fi, kami_fo);
	}
	ios_base::sync_with_stdio(0);
	cin.tie(0);
}

void just_do_it();

void just_exec_it() {
	if (kami_loc) {
		auto pstart = chrono::steady_clock::now();
		just_do_it();
		auto pend = chrono::steady_clock::now();
		long long ptime = chrono::duration_cast<chrono::milliseconds>(pend - pstart).count();
		string bar(50, '=');
		cout << '\n' << bar << '\n';
		cout << "Time: " << ptime << " ms" << '\n';
	}
	else {
		just_do_it();
	}
}

int main() {
	set_up();
	just_exec_it();
	return 0;
}

// END BOILERPLATE CODE

// BEGIN MAIN CODE

const int ms = 1e5 + 20;
const int st = 20;
int nxt[ms][st];
int lt[ms];
int rt[ms];

void just_do_it() {
	int n, q;
	cin >> n >> q;
	vector<pair<int, int>> p;
	for (int i = 1; i <= n; i++) {
		cin >> lt[i] >> rt[i];
		p.push_back({lt[i], -i});
		p.push_back({rt[i], i});
	}
	sort(p.begin(), p.end());
	set<pair<int, int>> s;
	for (auto x: p) {
		if (x.second < 0) {
			s.insert({rt[-x.second], -x.second});
		}
		else {
			nxt[x.second][0] = s.rbegin()->second;
			s.erase({rt[x.second], x.second});
		}
	}
	for (int k = 1; k < st; k++) {
		for (int i = 1; i <= n; i++) {
			nxt[i][k] = nxt[nxt[i][k - 1]][k - 1];
		}
	}
	for (int i = 0; i < q; i++) {
		int u, v;
		cin >> u >> v;
		if (u == v) {
			cout << 0 << '\n';
			continue;
		}
		if (rt[u] > rt[v]) {
			cout << "impossible" << '\n';
			continue;
		}
		int res = 0;
		for (int k = st - 1; k >= 0; k--) {
			if (rt[nxt[u][k]] < rt[v]) {
				u = nxt[u][k];
				res |= 1 << k;
			}
		}
		if (rt[nxt[u][0]] < rt[v]) {
			cout << "impossible" << '\n';
		}
		else {
			res++;
			cout << res << '\n';
		}
	}
}

// END MAIN CODE

Compilation message

events.cpp: In function 'void file_io(std::string, std::string)':
events.cpp:30:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |   freopen(fi.c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
events.cpp:33:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |   freopen(fo.c_str(), "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 212 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Incorrect 0 ms 340 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Incorrect 0 ms 340 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Incorrect 0 ms 340 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 99 ms 11120 KB Output is correct
2 Correct 133 ms 11200 KB Output is correct
3 Correct 121 ms 11208 KB Output is correct
4 Correct 93 ms 11624 KB Output is correct
5 Correct 110 ms 11524 KB Output is correct
6 Correct 114 ms 11388 KB Output is correct
7 Correct 145 ms 14452 KB Output is correct
8 Correct 104 ms 14484 KB Output is correct
9 Correct 92 ms 17120 KB Output is correct
10 Correct 106 ms 14080 KB Output is correct
11 Correct 101 ms 14912 KB Output is correct
12 Correct 99 ms 14064 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 212 KB Output isn't correct
2 Halted 0 ms 0 KB -