CSES - Putka Open 2015 – 1/6 - Results
Submission details
Task:Lähetit
Sender:
Submission time:2015-07-19 22:11:51 +0300
Language:C++
Status:READY
Result:35
Feedback
groupverdictscore
#1ACCEPTED12
#2ACCEPTED23
#30
Test results
testverdicttimegroup
#1ACCEPTED0.08 s1details
#2ACCEPTED0.09 s1details
#3ACCEPTED0.08 s1details
#4ACCEPTED0.09 s1details
#5ACCEPTED0.08 s1details
#6ACCEPTED0.09 s2details
#7ACCEPTED0.08 s2details
#8ACCEPTED0.10 s2details
#9ACCEPTED0.09 s2details
#10ACCEPTED0.08 s2details
#110.07 s3details
#120.08 s3details
#130.08 s3details
#140.08 s3details
#15ACCEPTED0.07 s3details

Code

#include <iostream>
#include <vector>
#include <algorithm>
#include <unordered_map>

using namespace std;

#define ll long long
#define N 1000000007

int n,k;
ll d[101][101];
ll s[101][101];

int main()
{
	cin >> n >> k;
	if (k > 2*n-2) {
		cout << 0 << "\n";
		return 0;
	}
	s[0][0] = 1;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= i; j++) {
			s[i][j] = j*s[i-1][j]+s[i-1][j-1];
		}
	}
	for (int i = 0; i <= n; i++) {
		d[i][0] = 1;
		for (int j = 1; j <= i; j++) {
			d[i][j] = d[i-1][j-1]+d[i-1][j];
		}
	}
	ll sum = 0;
	for (int i = max(0,k-n); i <= min(k,n); i++) {
		ll first = 0;
		for (int j = 0; j <= (n+1)/2; j++) {
			first += d[(n+1)/2][j]*s[j+n/2][n-i];
			first %= N;
		}
		ll second = 0;
		for (int j = 0; j <= n/2; j++) {
			second += d[n/2][j]*s[j+(n+1)/2][n-k+i];
			second %= N;
		}
		sum += (first*second)%N;
		sum %= N;
	}
	cout << sum%N << "\n";
}

Test details

Test 1

Group: 1

Verdict: ACCEPTED

input
5 2

correct output
240

user output
240

Test 2

Group: 1

Verdict: ACCEPTED

input
5 4

correct output
2728

user output
2728

Test 3

Group: 1

Verdict: ACCEPTED

input
5 6

correct output
1960

user output
1960

Test 4

Group: 1

Verdict: ACCEPTED

input
5 8

correct output
32

user output
32

Test 5

Group: 1

Verdict: ACCEPTED

input
5 10

correct output
0

user output
0

Test 6

Group: 2

Verdict: ACCEPTED

input
10 4

correct output
1809464

user output
1809464

Test 7

Group: 2

Verdict: ACCEPTED

input
10 8

correct output
209594075

user output
209594075

Test 8

Group: 2

Verdict: ACCEPTED

input
10 12

correct output
811277399

user output
811277399

Test 9

Group: 2

Verdict: ACCEPTED

input
10 16

correct output
17275136

user output
17275136

Test 10

Group: 2

Verdict: ACCEPTED

input
10 20

correct output
0

user output
0

Test 11

Group: 3

Verdict:

input
100 40

correct output
126883191

user output
-951704486

Test 12

Group: 3

Verdict:

input
100 80

correct output
785497039

user output
343620612

Test 13

Group: 3

Verdict:

input
100 120

correct output
324216296

user output
-391437441

Test 14

Group: 3

Verdict:

input
100 160

correct output
895190039

user output
-12067393

Test 15

Group: 3

Verdict: ACCEPTED

input
100 200

correct output
0

user output
0