oj.uz

Submission #724730

# Submission time Handle Problem Language Result Execution time Memory
724730 2023-04-15T19:42:14 Z 406 Sparklers (JOI17_sparklers) C++17
100 / 100
 70 ms 4424 KB 
#include "bits/stdc++.h"
#define int long long
#define dq deque<int>
using namespace std;
const long long INF = 1ll << 35;
const int N = 1e5 + 5;
int n, k, t, x[N];
dq L, R;

void ps(dq &v) {
	v.push_front(0);
	for (int i = 1; i < v.size(); i++) v[i] += v[i - 1];
}

array<int, 3> find(const dq &v) {
	int mn = v[0];
	for (int i = 1; i < v.size(); i++) {
		int u = v[i];
		mn = min(mn, u);
		if (u >= v[0]) return {u, mn, 1};
	}
	return {0, 0, 0};
}

bool solve(array<dq, 2> v, int d = 0) {
	if (v[0][0] + v[1][0] < 0 || v[1].back() + v[0].back() < 0) return false;

	assert(d <= 1);

	array<int, 3> A[2];
	A[0] = find(v[0]);
	A[1] = find(v[1]);

	while (v[0].size() > 1 && v[1].size() > 1) {
		//cout << v[0].size() << ' ' << v[1].size() << endl;
		bool flag = false;

		for (int k = 0; k < 2; k++) if (A[k][2]) {
			if (v[k ^ 1][0] + A[k][1] >= 0) {
				v[k].pop_front();
				while (v[k][0] != A[k][0]) v[k].pop_front();
				A[k] = find(v[k]);
				flag = true;
			}
		}

		if (flag) continue;
		else if (A[0][2] && A[1][2]) return false;

		if (!A[0][2] && !A[1][2]) {
			for (int k = 0; k < 2; k++) reverse(v[k].begin(), v[k].end());
			return solve(v, d + 1);
		}
		else return false;
	}
	for (int k = 0; k < 2; k++) if (v[k].size() > 1) {
		for (auto u: v[k]) if (u + v[1 ^ k][0] < 0) return false;
	}
	return true;
}

bool check(int O) {
	int s = O * 2 * t;
	dq l = L, r = R;
	for (auto &u: l) u = s - u;
	for (auto &u: r) u = s - u;
	ps(l), ps(r);

	/*
	for (auto u: l) cout << u << ' ';
	cout << endl;
	for (auto u: r) cout << u << ' ';
	cout << endl;
	*/

	return solve(array<dq, 2>{l, r});
}

void rand_test();

signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> n >> k >> t;
	k--;

	for (int i = 0; i < n; i++) cin >> x[i];
	for (int i = 0; i < k; i++)
		L.push_back(x[i + 1] - x[i]);	
	reverse(L.begin(), L.end());
	for (int i = k + 1; i < n; i++) 
		R.push_back(x[i] - x[i - 1]);

	int l = -1, r = INF;
	while (r - l > 1) {
		int m = l + r >> 1;
		if (check(m)) r = m;
		else l = m;
	}
	cout << r << '\n';
	return 0;
}

void rand_test() {
	for (int i = 0; i < 20; i++) L.push_back(rand() % 10);
	for (int i = 0; i < 20; i++) R.push_back(rand() % 10);
	for (auto u: L) cout << u << ' ';
	cout << endl;
	for (auto u: R) cout << u << ' ';
	cout << endl;
	solve(array<dq, 2>{L, R});
}

Compilation message

sparklers.cpp: In function 'void ps(std::deque<long long int>&)':
sparklers.cpp:12:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::deque<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |  for (int i = 1; i < v.size(); i++) v[i] += v[i - 1];
      |                  ~~^~~~~~~~~~
sparklers.cpp: In function 'std::array<long long int, 3> find(const std::deque<long long int>&)':
sparklers.cpp:17:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::deque<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |  for (int i = 1; i < v.size(); i++) {
      |                  ~~^~~~~~~~~~
sparklers.cpp: In function 'int main()':
sparklers.cpp:96:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   96 |   int m = l + r >> 1;
      |           ~~^~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 228 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 0 ms 340 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 0 ms 212 KB Output is correct
21 Correct 0 ms 340 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 228 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 0 ms 340 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 0 ms 212 KB Output is correct
21 Correct 0 ms 340 KB Output is correct
22 Correct 1 ms 340 KB Output is correct
23 Correct 1 ms 340 KB Output is correct
24 Correct 1 ms 340 KB Output is correct
25 Correct 1 ms 340 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 1 ms 468 KB Output is correct
28 Correct 1 ms 340 KB Output is correct
29 Correct 1 ms 340 KB Output is correct
30 Correct 1 ms 340 KB Output is correct
31 Correct 1 ms 340 KB Output is correct
32 Correct 1 ms 340 KB Output is correct
33 Correct 1 ms 340 KB Output is correct
34 Correct 1 ms 340 KB Output is correct
35 Correct 1 ms 340 KB Output is correct
36 Correct 1 ms 368 KB Output is correct
37 Correct 1 ms 340 KB Output is correct
38 Correct 1 ms 340 KB Output is correct
39 Correct 1 ms 340 KB Output is correct
40 Correct 1 ms 340 KB Output is correct

Subtask #3
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 228 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 0 ms 340 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 0 ms 212 KB Output is correct
21 Correct 0 ms 340 KB Output is correct
22 Correct 1 ms 340 KB Output is correct
23 Correct 1 ms 340 KB Output is correct
24 Correct 1 ms 340 KB Output is correct
25 Correct 1 ms 340 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 1 ms 468 KB Output is correct
28 Correct 1 ms 340 KB Output is correct
29 Correct 1 ms 340 KB Output is correct
30 Correct 1 ms 340 KB Output is correct
31 Correct 1 ms 340 KB Output is correct
32 Correct 1 ms 340 KB Output is correct
33 Correct 1 ms 340 KB Output is correct
34 Correct 1 ms 340 KB Output is correct
35 Correct 1 ms 340 KB Output is correct
36 Correct 1 ms 368 KB Output is correct
37 Correct 1 ms 340 KB Output is correct
38 Correct 1 ms 340 KB Output is correct
39 Correct 1 ms 340 KB Output is correct
40 Correct 1 ms 340 KB Output is correct
41 Correct 36 ms 2420 KB Output is correct
42 Correct 2 ms 340 KB Output is correct
43 Correct 11 ms 852 KB Output is correct
44 Correct 47 ms 3572 KB Output is correct
45 Correct 58 ms 3584 KB Output is correct
46 Correct 58 ms 3608 KB Output is correct
47 Correct 56 ms 3668 KB Output is correct
48 Correct 60 ms 3592 KB Output is correct
49 Correct 49 ms 3672 KB Output is correct
50 Correct 64 ms 3580 KB Output is correct
51 Correct 56 ms 3572 KB Output is correct
52 Correct 52 ms 3572 KB Output is correct
53 Correct 52 ms 3644 KB Output is correct
54 Correct 50 ms 3524 KB Output is correct
55 Correct 63 ms 3712 KB Output is correct
56 Correct 53 ms 3712 KB Output is correct
57 Correct 39 ms 3560 KB Output is correct
58 Correct 70 ms 3612 KB Output is correct
59 Correct 64 ms 3624 KB Output is correct
60 Correct 45 ms 4376 KB Output is correct
61 Correct 53 ms 3588 KB Output is correct
62 Correct 51 ms 3648 KB Output is correct
63 Correct 53 ms 4424 KB Output is correct
64 Correct 55 ms 4388 KB Output is correct
65 Correct 60 ms 4384 KB Output is correct
66 Correct 69 ms 3556 KB Output is correct
67 Correct 58 ms 3572 KB Output is correct
68 Correct 48 ms 4316 KB Output is correct
69 Correct 45 ms 4364 KB Output is correct