| Task: | Lähetit |
| Sender: | |
| Submission time: | 2015-07-19 20:32:45 +0300 |
| Language: | C++ |
| Status: | READY |
| Result: | 100 |
| group | verdict | score |
|---|---|---|
| #1 | ACCEPTED | 12 |
| #2 | ACCEPTED | 23 |
| #3 | ACCEPTED | 65 |
| test | verdict | time | group | |
|---|---|---|---|---|
| #1 | ACCEPTED | 0.07 s | 1 | details |
| #2 | ACCEPTED | 0.08 s | 1 | details |
| #3 | ACCEPTED | 0.08 s | 1 | details |
| #4 | ACCEPTED | 0.09 s | 1 | details |
| #5 | ACCEPTED | 0.09 s | 1 | details |
| #6 | ACCEPTED | 0.09 s | 2 | details |
| #7 | ACCEPTED | 0.09 s | 2 | details |
| #8 | ACCEPTED | 0.08 s | 2 | details |
| #9 | ACCEPTED | 0.07 s | 2 | details |
| #10 | ACCEPTED | 0.08 s | 2 | details |
| #11 | ACCEPTED | 0.09 s | 3 | details |
| #12 | ACCEPTED | 0.08 s | 3 | details |
| #13 | ACCEPTED | 0.08 s | 3 | details |
| #14 | ACCEPTED | 0.08 s | 3 | details |
| #15 | ACCEPTED | 0.07 s | 3 | details |
Code
#include <iostream>
typedef long long ll;
const ll MOD = 1e9+7;
using namespace std;
ll dp[101][101];
ll dp2[101][101];
int main() {
int n,k;
cin>>n>>k;
if(n%2 == 0) {
dp[1][0] = 1;
dp[1][1] = 2;
for(int i = 3; i < n; i += 2) {
for(int j = 0; j <= i-2; ++j) {
int left = i-j;
dp[i][j] += dp[i-2][j];
dp[i][j] %= MOD;
dp[i][j+1] += dp[i-2][j]*left*2;
dp[i][j+1] %= MOD;
dp[i][j+2] += dp[i-2][j] * left %MOD * (left-1);
dp[i][j+2] %= MOD;
}
}
ll ans = 0;
for(int i = 0; i <= k; ++i) {
ans += dp[n-1][i] * dp[n-1][k-i];
ans %= MOD;
}
cout<<ans<<'\n';
}
else {
dp[1][0] = 1;
dp[1][1] = 2;
for(int i = 3; i < n; i += 2) {
for(int j = 0; j <= i-2; ++j) {
int left = i-j;
dp[i][j] += dp[i-2][j];
dp[i][j] %= MOD;
dp[i][j+1] += dp[i-2][j]*left*2;
dp[i][j+1] %= MOD;
dp[i][j+2] += dp[i-2][j] * left %MOD * (left-1);
dp[i][j+2] %= MOD;
}
}
for(int j = 0; j <= n-2; ++j) {
int left = n-j;
dp[n-1][j] += dp[n-2][j];
dp[n-1][j] %= MOD;
dp[n-1][j+1] += dp[n-2][j]*left;
dp[n-1][j+1] %= MOD;
}
dp2[1][0] = 1;
dp2[1][1] = 4;
dp2[1][2] = 2;
for(int i = 3; i < n; i += 2) {
for(int j = 0; j <= i-1; ++j) {
int left = i+1-j;
dp2[i][j] += dp2[i-2][j];
dp2[i][j] %= MOD;
dp2[i][j+1] += dp2[i-2][j]*left*2;
dp2[i][j+1] %= MOD;
dp2[i][j+2] += dp2[i-2][j] * left %MOD * (left-1);
dp2[i][j+2] %= MOD;
}
}
ll ans = 0;
for(int i = 0; i <= k; ++i) {
ans += dp[n-1][i] * dp2[n-2][k-i];
ans %= MOD;
}
cout<<ans<<'\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 |