oj.uz

Submission #586608

# Submission time Handle Problem Language Result Execution time Memory
586608 2022-06-30T12:34:50 Z blue Skyscraper (JOI16_skyscraper) C++17
100 / 100
 229 ms 119960 KB 
#include <iostream>
#include <vector>
#include <algorithm>
#include <cassert>
using namespace std;

using ll = long long;
using vll = vector<ll>;
using vi = vector<int>;

const ll mod = 1'000'000'007LL;

ll ad(ll a, ll b)
{
	return (a+b) % mod;
}

ll mul(ll a, ll b)
{
	return (a*b) % mod;
}

void selfadd(int& a, int b)
{
	a = ad(a, b);
}

int N, L;

int validlen(int x)
{
	return 0 <= x && x <= L;
}

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	cin >> N >> L;

	vi A(1+N, 0);
	for(int i = 1; i <= N; i++)
		cin >> A[i];

	sort(A.begin(), A.end());

	int DP[1+N][1+N][1+L][1+2];

	for(int i = 0; i <= N; i++)
		for(int j = 0; j <= N; j++)
			for(int l = 0; l <= L; l++)
				for(int e = 0; e <= 2; e++)
					DP[i][j][l][e] = 0;

	DP[1][1][0][0] = DP[1][1][0][2] = 1;
	DP[1][1][0][1] = 2;

	for(int i = 1; i <= N; i++)
	{
		// cerr << "\n\n\n";
		for(int j = 1; j <= i; j++)
		{
			// cerr << "\n\n";
			for(int l = 0; l <= L; l++)
			{
				// cerr << "\n";
				for(int e = 0; e <= 2; e++)
				{
					// cerr << i << ' ' << j << ' ' << l << ' ' << e << " : " << DP[i][j][l][e] << '\n';

					if(i >= N)
						continue;

					int nl = l + (2*j - e) * (A[i+1] - A[i]);

					if(!validlen(nl))
						continue;

					// cerr << "proceeding\n";


					//case 1: building i+1 forms new component
		selfadd(DP[i+1][j+1][nl][e], mul(DP[i][j][l][e], j+1 - e));

		           //case 2: building i+1 is attached to the left/right of some component
		// if(i == 1 && j == 1 && l == 0 && e == 0)
			// cerr << DP[i][j][l][e] << ' ' << 2*j - e << " -> " << i+1 << ' ' << j << ' ' << l + (2*j - e) * (A[i+1] - A[i]) << ' ' << e << '\n';
		selfadd(DP[i+1][j][nl][e], mul(DP[i][j][l][e], 2*j - e));

				   //case 3: building i+1 merges two components
					if(j >= 2)
		selfadd(DP[i+1][j-1][nl][e], mul(DP[i][j][l][e], j-1));

				   //case 4: building i+1 creates an endpoint
					if(e < 2)
		selfadd(DP[i+1][j][nl][e+1], mul(DP[i][j][l][e], 2 - e));

					//case 5: building i+1 simultaneously forms a new component and creates endpoint
	                if(e < 2)
	    selfadd(DP[i+1][j+1][nl][e+1], mul(DP[i][j][l][e], 2 - e));
					}
			}
		}
	}

	ll res = 0;

	for(int l = 0; l <= L; l++)
		res = ad(res, DP[N][1][l][2]);

	assert(0 <= res && res < mod);

	cout << res << '\n';
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 2 ms 1108 KB Output is correct
6 Correct 1 ms 1108 KB Output is correct
7 Correct 0 ms 468 KB Output is correct
8 Correct 0 ms 340 KB Output is correct
9 Correct 1 ms 1108 KB Output is correct
10 Correct 1 ms 340 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 468 KB Output is correct

Subtask #3
80.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 2 ms 1108 KB Output is correct
6 Correct 1 ms 1108 KB Output is correct
7 Correct 0 ms 468 KB Output is correct
8 Correct 0 ms 340 KB Output is correct
9 Correct 1 ms 1108 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 468 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 1 ms 468 KB Output is correct
20 Correct 1 ms 468 KB Output is correct
21 Correct 2 ms 980 KB Output is correct
22 Correct 166 ms 60612 KB Output is correct
23 Correct 223 ms 117968 KB Output is correct
24 Correct 195 ms 89164 KB Output is correct
25 Correct 228 ms 119476 KB Output is correct
26 Correct 191 ms 101580 KB Output is correct
27 Correct 72 ms 29636 KB Output is correct
28 Correct 89 ms 36308 KB Output is correct
29 Correct 181 ms 68804 KB Output is correct
30 Correct 229 ms 119960 KB Output is correct