CSES - Putka Open 2015 – 1/6 - Results
Submission details
Task:Lähetit
Sender:
Submission time:2015-07-19 19:01:41 +0300
Language:C++
Status:READY
Result:100
Feedback
groupverdictscore
#1ACCEPTED12
#2ACCEPTED23
#3ACCEPTED65
Test results
testverdicttimegroup
#1ACCEPTED0.09 s1details
#2ACCEPTED0.09 s1details
#3ACCEPTED0.08 s1details
#4ACCEPTED0.09 s1details
#5ACCEPTED0.08 s1details
#6ACCEPTED0.09 s2details
#7ACCEPTED0.07 s2details
#8ACCEPTED0.08 s2details
#9ACCEPTED0.09 s2details
#10ACCEPTED0.08 s2details
#11ACCEPTED0.09 s3details
#12ACCEPTED0.07 s3details
#13ACCEPTED0.09 s3details
#14ACCEPTED0.07 s3details
#15ACCEPTED0.09 s3details

Code

#include <iostream>

#define ll long long
#define M 1000000007

using namespace std;

ll n, k;
ll bl[101][101], wh[101][101];

int main() {
	cin >> n >> k;
	bl[0][0] = 1;
	for (ll i=1;i<=n;i+=2) {
		bl[i][0] = 1;
		ll tmp = 2;
		if (i == n) tmp = 1;
		for (ll j=1;j<=n;j++) {
			bl[i][j] = bl[i-1][j];
			bl[i][j] += bl[i-1][j-1]*tmp*(i-j+1);
			bl[i][j] %= M;
			if (j<2) continue;
			bl[i][j] += 
bl[i-1][j-2]*(tmp/2)*(i-j+2)*(tmp-1)*(i-j+1);
			bl[i][j] %= M;
		}
		for (int j=0;j<=n;j++) {
			bl[i+1][j] = bl[i][j];
		}
	}
	wh[1][0] = 1;
	for (ll i=2;i<=n;i+=2) {
		wh[i][0] = 1;
		ll tmp =2;
		if (i == n) tmp = 1;
		for (ll j=1;j<=n;j++) {
			wh[i][j] = wh[i-1][j];
			wh[i][j] += wh[i-1][j-1]*tmp*(i-j+1);
			wh[i][j] %= M;
			if (j<2) continue;
			wh[i][j] += 
wh[i-1][j-2]*(tmp/2)*(i-j+2)*(tmp-1)*(i-j+1);
			wh[i][j] %= M;
		}
		for (int j=0;j<=n;j++) {
			wh[i+1][j] = wh[i][j];
		}
	}
	ll res = 0;
	for (int i=0;i<=n;i++) {
		if (k-i > n) {
			i = k-n;
			continue;
		}
		if (k-i < 0) break;
		res += bl[n][i]*wh[n][k-i];
		res %= M;
	}
	cout << res << "\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: ACCEPTED

input
100 40

correct output
126883191

user output
126883191

Test 12

Group: 3

Verdict: ACCEPTED

input
100 80

correct output
785497039

user output
785497039

Test 13

Group: 3

Verdict: ACCEPTED

input
100 120

correct output
324216296

user output
324216296

Test 14

Group: 3

Verdict: ACCEPTED

input
100 160

correct output
895190039

user output
895190039

Test 15

Group: 3

Verdict: ACCEPTED

input
100 200

correct output
0

user output
0