oj.uz

Submission #916116

# Submission time Handle Problem Language Result Execution time Memory
916116 2024-01-25T10:27:15 Z redstonegamer22 Overtaking (IOI23_overtaking) C++17
65 / 100
 3500 ms 26264 KB 
#ifndef LOCAL
	#include "overtaking.h"
#endif // LOCAL
#ifdef LOCAL
	#define _GLIBCXX_DEBUG
	#include <vector>

	void init(int L, int N, std::vector<long long> T, std::vector<int> W, int X, int M, std::vector<int> S);

	long long arrival_time(long long Y);
#endif // LOCAL

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

const int time_infty = 1e18 + 7;
const int nmax = 1000 + 24;
const int nmax_bs_step = (1 << 10);

struct bus {
	int start_time;
	int speed;
};

vector<bus> glob_busses;
vector<vector<bus>> busses_by_station;
vector<vector<int>> endtime_of_bus_by_station;
vector<int> stations;
int X_init;

void precompute_strips() {
	// pentru fiecare statie, retin autobuzele ca perechi de (timp, viteza)
	auto busses = glob_busses;

	sort(busses.begin(), busses.end(), [](bus a, bus b) {
		if(a.start_time != b.start_time) 
			return a.start_time < b.start_time;
		return a.speed < b.speed;
	});

	busses_by_station.push_back(busses); // pentru statia 0

	for(int i = 0; i + 1 < stations.size(); i++) {
		int distance = stations[i + 1] - stations[i];

		int max_prefix = -1e9;

		vector<bus> new_busses;
		vector<int> new_endtime_of_bus;
		for(auto b : busses) {
			max_prefix = max(max_prefix, b.start_time + distance * b.speed);
			new_busses.push_back({max_prefix, b.speed});

			new_endtime_of_bus.push_back(max_prefix);
		}

		endtime_of_bus_by_station.push_back(new_endtime_of_bus);

		busses = new_busses;

		sort(busses.begin(), busses.end(), [](bus a, bus b) {
			if(a.start_time != b.start_time) 
				return a.start_time < b.start_time;
			return a.speed < b.speed;
		});

		busses_by_station.push_back(busses);
	}
}

struct intervals {
	int start, end;

	bool operator<(const intervals &other) const {
		if(start != other.start) return start < other.start;
		return end < other.end;
	}

	bool operator==(const intervals &other) const {
		return start == other.start && end == other.end;
	}
};
// daca eu ma aflu la timpul Y si Y intre [start, end], atunci
// eu voi termina la timpul end la final

set<intervals> solution_set;

long long arrival_time_fast(long long Y) {
	// care doar da query in structura curenta a solution_set-ului
	// si returneaza timpul de sosire

	// cautam in solution_set intervalul care contine Y
	auto it = solution_set.lower_bound({Y, time_infty});
	if(it == solution_set.begin()) {
		// nu exista niciun interval care sa contina Y
		return Y;
	}

	auto interval = *prev(it);

	if(Y < interval.start || Y > interval.end) {
		// nu exista niciun interval care sa contina Y
		return Y;
	}

	return interval.end;
}

long long query_strip(int strip_index, long long Y) {
	// strip-ul se intinde de la stations[strip_index] la stations[strip_index + 1]

	// cautam in busses_by_station[strip_index] autobuzul care ma tine in spate

	// facem o cautare binara pentru ultimul autobuz care (conform comparatorului custom) este
	// mai mic decat mine

	const auto& busses = busses_by_station[strip_index]; // O(1)
	const auto& endtime_of_bus = endtime_of_bus_by_station[strip_index]; // O(1)

	int ok = -1;
	for(int step = nmax_bs_step; step >= 1; step /= 2) {
		while(ok + step < busses.size() && busses[ok + step].start_time < Y) {
			ok += step;
		}
	}

	if(ok == -1) {
		// nu exista niciun autobuz care sa ma tina in spate
		return Y;
	}

	if(endtime_of_bus[ok] < Y) {
		// nu exista niciun autobuz care sa ma tina in spate
		return Y;
	}

	return endtime_of_bus[ok];
}

void add_strip(int strip_index) {
	// adaugam un nou strip in solution_set
	// practic la final sa dam query(Y) <=> Y' = query_strip(strip_index, Y) si apoi Y'' = arrival_time_fast(Y')

	set<intervals> new_solution_set;
}

#undef int
void init(int L, int N, std::vector<long long> T, std::vector<int> W, int X, int M, std::vector<int> S) {
#define int long long
	// scad X (viteza autobuzului de query) din fiecare viteza de autobuz (W)
	for(int i = 0; i < N; ++i) {
		W[i] -= X;
	}
	X_init = X;

	// initialize busses
	for(int i = 0; i < N; ++i) {
		bus b;
		b.start_time = T[i];
		b.speed = W[i];

		if(W[i] <= 0) continue; // acest autobuz nu afecteaza autobuzul meu!

		glob_busses.push_back(b);
	}

	// initialize stations
	for(int i = 0; i < M; ++i) {
		stations.push_back(S[i]);
	}

	precompute_strips();
}

long long arrival_time_brut(long long Y) {
	auto busses = glob_busses;
	busses.push_back({Y, 0}); // autobuzul meu incepe la timpul Y si are viteza 0

	sort(busses.begin(), busses.end(), [](bus a, bus b) {
		if(a.start_time != b.start_time) 
			return a.start_time < b.start_time;
		return a.speed < b.speed;
	});

	for(int i = 0; i + 1 < stations.size(); i++) {
		int distance = stations[i + 1] - stations[i];

		int max_prefix = -1e9;

		vector<bus> new_busses;
		for(auto b : busses) {
			max_prefix = max(max_prefix, b.start_time + distance * b.speed);
			new_busses.push_back({max_prefix, b.speed});
		}

		busses = new_busses;

		sort(busses.begin(), busses.end(), [](bus a, bus b) {
			if(a.start_time != b.start_time) 
				return a.start_time < b.start_time;
			return a.speed < b.speed;
		});
	}

	for(auto b : busses) {
		if(b.speed == 0) return b.start_time;
	}

	assert(false); // nu se poate ajunge aici
}

long long arrival_time_slow(long long Y) {
	// repeatedly use query_strip()

	for(int strip_index = 0; strip_index + 1 < stations.size(); strip_index++) {
		Y = query_strip(strip_index, Y);
	}

	return Y;
}

long long arrival_time(long long Y) {
	long long answer = arrival_time_slow(Y);
	#ifdef LOCAL
		assert (answer == arrival_time_brut(Y));
	#endif // LOCAL
	return answer + 1LL * (stations.back() - stations[0]) * X_init;
}

#ifdef LOCAL
#undef int
// Grader
#include <cassert>
#include <cstdio>
#include <vector>

int main()
{
    int L, N, X, M, Q;
    assert(5 == scanf("%d %d %d %d %d", &L, &N, &X, &M, &Q));
    std::vector<long long> T(N);
    for (int i = 0; i < N; i++)
        assert(1 == scanf("%lld", &T[i]));
    std::vector<int> W(N);
    for (int i = 0; i < N; i++)
        assert(1 == scanf("%d", &W[i]));
    std::vector<int> S(M);
    for (int i = 0; i < M; i++)
        assert(1 == scanf("%d", &S[i]));
    std::vector<long long> Y(Q);
    for (int i = 0; i < Q; i++)
        assert(1 == scanf("%lld", &Y[i]));

    fclose(stdin);

    init(L, N, T, W, X, M, S);
    std::vector<long long> res(Q);
    for (int i = 0; i < Q; i++)
        res[i] = arrival_time(Y[i]);

    for (int i = 0; i < Q; i++)
        printf("%lld\n", res[i]);
    fclose(stdout);
    return 0;
}
#endif // LOCAL

Compilation message

overtaking.cpp: In function 'void precompute_strips()':
overtaking.cpp:45:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |  for(int i = 0; i + 1 < stations.size(); i++) {
      |                 ~~~~~~^~~~~~~~~~~~~~~~~
overtaking.cpp: In function 'long long int query_strip(long long int, long long int)':
overtaking.cpp:124:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<bus>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  124 |   while(ok + step < busses.size() && busses[ok + step].start_time < Y) {
      |         ~~~~~~~~~~^~~~~~~~~~~~~~~
overtaking.cpp: In function 'long long int arrival_time_brut(long long int)':
overtaking.cpp:187:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  187 |  for(int i = 0; i + 1 < stations.size(); i++) {
      |                 ~~~~~~^~~~~~~~~~~~~~~~~
overtaking.cpp: In function 'long long int arrival_time_slow(long long int)':
overtaking.cpp:217:43: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  217 |  for(int strip_index = 0; strip_index + 1 < stations.size(); strip_index++) {
      |                           ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~

Subtask #0
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 2 ms 348 KB Output is correct
6 Correct 6 ms 348 KB Output is correct
7 Correct 11 ms 568 KB Output is correct
8 Correct 13 ms 348 KB Output is correct
9 Correct 13 ms 576 KB Output is correct
10 Correct 17 ms 348 KB Output is correct
11 Correct 12 ms 348 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 1 ms 344 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Correct 1 ms 348 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 600 KB Output is correct
10 Correct 1 ms 600 KB Output is correct
11 Correct 2 ms 600 KB Output is correct
12 Correct 1 ms 604 KB Output is correct
13 Correct 1 ms 604 KB Output is correct
14 Correct 1 ms 604 KB Output is correct
15 Correct 1 ms 604 KB Output is correct
16 Correct 2 ms 604 KB Output is correct
17 Correct 2 ms 604 KB Output is correct
18 Correct 1 ms 600 KB Output is correct
19 Correct 1 ms 860 KB Output is correct
20 Correct 1 ms 604 KB Output is correct
21 Correct 1 ms 348 KB Output is correct
22 Correct 1 ms 568 KB Output is correct
23 Correct 1 ms 604 KB Output is correct
24 Correct 1 ms 604 KB Output is correct
25 Correct 1 ms 648 KB Output is correct
26 Correct 1 ms 604 KB Output is correct
27 Correct 1 ms 600 KB Output is correct
28 Correct 1 ms 348 KB Output is correct
29 Correct 1 ms 344 KB Output is correct
30 Correct 1 ms 348 KB Output is correct
31 Correct 1 ms 348 KB Output is correct
32 Correct 1 ms 604 KB Output is correct
33 Correct 1 ms 604 KB Output is correct
34 Correct 1 ms 604 KB Output is correct
35 Correct 1 ms 604 KB Output is correct
36 Correct 1 ms 604 KB Output is correct
37 Correct 1 ms 604 KB Output is correct
38 Correct 1 ms 348 KB Output is correct
39 Correct 0 ms 348 KB Output is correct
40 Correct 1 ms 604 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 2 ms 348 KB Output is correct
7 Correct 6 ms 348 KB Output is correct
8 Correct 11 ms 568 KB Output is correct
9 Correct 13 ms 348 KB Output is correct
10 Correct 13 ms 576 KB Output is correct
11 Correct 17 ms 348 KB Output is correct
12 Correct 12 ms 348 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 1 ms 600 KB Output is correct
17 Correct 1 ms 600 KB Output is correct
18 Correct 2 ms 600 KB Output is correct
19 Correct 1 ms 604 KB Output is correct
20 Correct 1 ms 604 KB Output is correct
21 Correct 1 ms 604 KB Output is correct
22 Correct 1 ms 604 KB Output is correct
23 Correct 2 ms 604 KB Output is correct
24 Correct 2 ms 604 KB Output is correct
25 Correct 1 ms 600 KB Output is correct
26 Correct 1 ms 860 KB Output is correct
27 Correct 1 ms 604 KB Output is correct
28 Correct 1 ms 348 KB Output is correct
29 Correct 1 ms 568 KB Output is correct
30 Correct 1 ms 604 KB Output is correct
31 Correct 1 ms 604 KB Output is correct
32 Correct 1 ms 648 KB Output is correct
33 Correct 1 ms 604 KB Output is correct
34 Correct 1 ms 600 KB Output is correct
35 Correct 1 ms 348 KB Output is correct
36 Correct 1 ms 344 KB Output is correct
37 Correct 1 ms 348 KB Output is correct
38 Correct 1 ms 348 KB Output is correct
39 Correct 1 ms 604 KB Output is correct
40 Correct 1 ms 604 KB Output is correct
41 Correct 1 ms 604 KB Output is correct
42 Correct 1 ms 604 KB Output is correct
43 Correct 1 ms 604 KB Output is correct
44 Correct 1 ms 604 KB Output is correct
45 Correct 1 ms 348 KB Output is correct
46 Correct 0 ms 348 KB Output is correct
47 Correct 1 ms 604 KB Output is correct
48 Correct 117 ms 23892 KB Output is correct
49 Correct 305 ms 24244 KB Output is correct
50 Correct 278 ms 24240 KB Output is correct
51 Correct 297 ms 24240 KB Output is correct
52 Correct 285 ms 24244 KB Output is correct
53 Correct 279 ms 24248 KB Output is correct
54 Correct 280 ms 24236 KB Output is correct
55 Correct 83 ms 24140 KB Output is correct
56 Correct 322 ms 24240 KB Output is correct
57 Correct 279 ms 24244 KB Output is correct
58 Correct 284 ms 24240 KB Output is correct
59 Correct 283 ms 24240 KB Output is correct
60 Correct 280 ms 24240 KB Output is correct
61 Correct 305 ms 24280 KB Output is correct
62 Correct 64 ms 600 KB Output is correct
63 Correct 2 ms 600 KB Output is correct
64 Correct 339 ms 12432 KB Output is correct
65 Correct 287 ms 12452 KB Output is correct
66 Correct 780 ms 24264 KB Output is correct
67 Correct 952 ms 24404 KB Output is correct
68 Correct 963 ms 24276 KB Output is correct
69 Correct 726 ms 24240 KB Output is correct
70 Correct 839 ms 24248 KB Output is correct
71 Correct 854 ms 24248 KB Output is correct
72 Correct 817 ms 24408 KB Output is correct
73 Correct 802 ms 24248 KB Output is correct
74 Correct 827 ms 24244 KB Output is correct
75 Correct 57 ms 700 KB Output is correct
76 Correct 58 ms 604 KB Output is correct
77 Correct 57 ms 604 KB Output is correct
78 Correct 264 ms 24204 KB Output is correct

Subtask #5
0.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 2 ms 348 KB Output is correct
7 Correct 6 ms 348 KB Output is correct
8 Correct 11 ms 568 KB Output is correct
9 Correct 13 ms 348 KB Output is correct
10 Correct 13 ms 576 KB Output is correct
11 Correct 17 ms 348 KB Output is correct
12 Correct 12 ms 348 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 1 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 1 ms 348 KB Output is correct
19 Correct 1 ms 348 KB Output is correct
20 Correct 1 ms 344 KB Output is correct
21 Correct 1 ms 348 KB Output is correct
22 Correct 1 ms 348 KB Output is correct
23 Correct 1 ms 348 KB Output is correct
24 Correct 1 ms 348 KB Output is correct
25 Correct 1 ms 348 KB Output is correct
26 Correct 1 ms 348 KB Output is correct
27 Correct 1 ms 600 KB Output is correct
28 Correct 1 ms 600 KB Output is correct
29 Correct 2 ms 600 KB Output is correct
30 Correct 1 ms 604 KB Output is correct
31 Correct 1 ms 604 KB Output is correct
32 Correct 1 ms 604 KB Output is correct
33 Correct 1 ms 604 KB Output is correct
34 Correct 2 ms 604 KB Output is correct
35 Correct 2 ms 604 KB Output is correct
36 Correct 1 ms 600 KB Output is correct
37 Correct 1 ms 860 KB Output is correct
38 Correct 1 ms 604 KB Output is correct
39 Correct 1 ms 348 KB Output is correct
40 Correct 1 ms 568 KB Output is correct
41 Correct 1 ms 604 KB Output is correct
42 Correct 1 ms 604 KB Output is correct
43 Correct 1 ms 648 KB Output is correct
44 Correct 1 ms 604 KB Output is correct
45 Correct 1 ms 600 KB Output is correct
46 Correct 1 ms 348 KB Output is correct
47 Correct 1 ms 344 KB Output is correct
48 Correct 1 ms 348 KB Output is correct
49 Correct 1 ms 348 KB Output is correct
50 Correct 1 ms 604 KB Output is correct
51 Correct 1 ms 604 KB Output is correct
52 Correct 1 ms 604 KB Output is correct
53 Correct 1 ms 604 KB Output is correct
54 Correct 1 ms 604 KB Output is correct
55 Correct 1 ms 604 KB Output is correct
56 Correct 1 ms 348 KB Output is correct
57 Correct 0 ms 348 KB Output is correct
58 Correct 1 ms 604 KB Output is correct
59 Correct 117 ms 23892 KB Output is correct
60 Correct 305 ms 24244 KB Output is correct
61 Correct 278 ms 24240 KB Output is correct
62 Correct 297 ms 24240 KB Output is correct
63 Correct 285 ms 24244 KB Output is correct
64 Correct 279 ms 24248 KB Output is correct
65 Correct 280 ms 24236 KB Output is correct
66 Correct 83 ms 24140 KB Output is correct
67 Correct 322 ms 24240 KB Output is correct
68 Correct 279 ms 24244 KB Output is correct
69 Correct 284 ms 24240 KB Output is correct
70 Correct 283 ms 24240 KB Output is correct
71 Correct 280 ms 24240 KB Output is correct
72 Correct 305 ms 24280 KB Output is correct
73 Correct 64 ms 600 KB Output is correct
74 Correct 2 ms 600 KB Output is correct
75 Correct 339 ms 12432 KB Output is correct
76 Correct 287 ms 12452 KB Output is correct
77 Correct 780 ms 24264 KB Output is correct
78 Correct 952 ms 24404 KB Output is correct
79 Correct 963 ms 24276 KB Output is correct
80 Correct 726 ms 24240 KB Output is correct
81 Correct 839 ms 24248 KB Output is correct
82 Correct 854 ms 24248 KB Output is correct
83 Correct 817 ms 24408 KB Output is correct
84 Correct 802 ms 24248 KB Output is correct
85 Correct 827 ms 24244 KB Output is correct
86 Correct 57 ms 700 KB Output is correct
87 Correct 58 ms 604 KB Output is correct
88 Correct 57 ms 604 KB Output is correct
89 Correct 264 ms 24204 KB Output is correct
90 Execution timed out 3556 ms 26264 KB Time limit exceeded
91 Halted 0 ms 0 KB -