#include<iostream>
using namespace std;
#define MOD 1000000007
typedef long long int lld;
lld DP[6000][6000];
lld trabalha(int x, int y){
if(x<0 || y<0)return 0;
if(DP[x][y]!=-1)return DP[x][y];
lld ans=0;
ans+=trabalha(x-1,y);
ans%=MOD;
ans+=4*y*trabalha(x-1,y-1);
ans%=MOD;
lld comb=y*(y-1);
comb/=2;
comb%=MOD;
//cout<<ans<<endl;
ans+=comb*trabalha(x-1,y-2);
comb=y*(x-1);
comb%=MOD;
//cout<<ans<<endl;
ans+=comb*trabalha(x-2,y-1);
ans%=MOD;
DP[x][y]=ans;
return ans;
}
int main(){
for(int i=0;i<6000;i++){
for(int j=0;j<6000;j++){
DP[i][j]=-1;
if(i==0 || j==0)DP[i][j]=1;
}
}
int x,y;
cin>>x>>y;
cout<<(trabalha(x,y)+MOD-1)%MOD<<endl;
/*for(int i=0;i<=x;i++){
for(int j=0;j<=y;j++){
cout<<i<<" "<<j<<" "<<DP[i][j]<<endl;
}
}*/
return 0;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
228 ms |
282236 KB |
Output is correct |
| 2 |
Correct |
206 ms |
282236 KB |
Output is correct |
| 3 |
Correct |
205 ms |
282296 KB |
Output is correct |
| 4 |
Correct |
228 ms |
282296 KB |
Output is correct |
| 5 |
Correct |
211 ms |
282464 KB |
Output is correct |
| 6 |
Correct |
210 ms |
282464 KB |
Output is correct |
| 7 |
Correct |
198 ms |
282464 KB |
Output is correct |
| 8 |
Correct |
218 ms |
282464 KB |
Output is correct |
| 9 |
Correct |
208 ms |
282464 KB |
Output is correct |
| 10 |
Correct |
223 ms |
282464 KB |
Output is correct |
| 11 |
Correct |
217 ms |
282464 KB |
Output is correct |
| 12 |
Correct |
219 ms |
282464 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
228 ms |
282236 KB |
Output is correct |
| 2 |
Correct |
206 ms |
282236 KB |
Output is correct |
| 3 |
Correct |
205 ms |
282296 KB |
Output is correct |
| 4 |
Correct |
228 ms |
282296 KB |
Output is correct |
| 5 |
Correct |
211 ms |
282464 KB |
Output is correct |
| 6 |
Correct |
210 ms |
282464 KB |
Output is correct |
| 7 |
Correct |
198 ms |
282464 KB |
Output is correct |
| 8 |
Correct |
218 ms |
282464 KB |
Output is correct |
| 9 |
Correct |
208 ms |
282464 KB |
Output is correct |
| 10 |
Correct |
223 ms |
282464 KB |
Output is correct |
| 11 |
Correct |
217 ms |
282464 KB |
Output is correct |
| 12 |
Correct |
219 ms |
282464 KB |
Output is correct |
| 13 |
Correct |
232 ms |
282464 KB |
Output is correct |
| 14 |
Correct |
242 ms |
282712 KB |
Output is correct |
| 15 |
Correct |
420 ms |
282776 KB |
Output is correct |
| 16 |
Correct |
235 ms |
282776 KB |
Output is correct |
| 17 |
Correct |
240 ms |
282776 KB |
Output is correct |
| 18 |
Correct |
254 ms |
282796 KB |
Output is correct |
| 19 |
Correct |
461 ms |
282796 KB |
Output is correct |
| 20 |
Correct |
413 ms |
282796 KB |
Output is correct |
| 21 |
Correct |
316 ms |
282796 KB |
Output is correct |
| 22 |
Correct |
304 ms |
282796 KB |
Output is correct |
| 23 |
Correct |
270 ms |
282796 KB |
Output is correct |
| 24 |
Correct |
564 ms |
282796 KB |
Output is correct |
| 25 |
Correct |
461 ms |
282796 KB |
Output is correct |
| 26 |
Correct |
523 ms |
282796 KB |
Output is correct |
| 27 |
Correct |
533 ms |
282896 KB |
Output is correct |
