#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
#define mp make_pair
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
int readint(){
int x=0,f=1; char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
return x*f;
}
const int cys=1e9+7;
int fct[355],inv[355];
void ckadd(int& x,int y){ x+=y; if(x>=cys) x-=cys; }
int ckmul(int x,int y){ return (1ll*x*y)%cys; }
int ckpow(int a,int b) { int res=1; for(;b;b>>=1,a=ckmul(a,a)){ if(b&1) res=ckmul(res,a); } return res; }
int C(int x,int y){ return ckmul(fct[x],ckmul(inv[y],inv[x-y])); }
void init(){
fct[0]=1;
for(int i=1;i<=350;i++) fct[i]=ckmul(fct[i-1],i);
inv[350]=ckpow(fct[350],cys-2);
for(int i=349;i>=0;i--) inv[i]=ckmul(inv[i+1],i+1);
}
int dp[355][355][2];
int main(){
init();
int n=readint();
dp[0][0][0]=1;
for(int i=1;i<=n;i++){
for(int x=0;x<=n;x++){
for(int f=0;f<2;f++){
for(int y=0;x+y<=n;y++){
int nf=(f|(y==i));
ckadd(dp[i][x+y][nf],ckmul(C(n-x,y),dp[i-1][x][f]));
}
}
}
}
printf("%d\n",dp[n][n][1]);
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
0 ms |
344 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
12 |
Correct |
0 ms |
348 KB |
Output is correct |
13 |
Correct |
1 ms |
348 KB |
Output is correct |
14 |
Correct |
0 ms |
348 KB |
Output is correct |
15 |
Correct |
0 ms |
348 KB |
Output is correct |
16 |
Correct |
1 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
0 ms |
344 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
12 |
Correct |
0 ms |
348 KB |
Output is correct |
13 |
Correct |
1 ms |
348 KB |
Output is correct |
14 |
Correct |
0 ms |
348 KB |
Output is correct |
15 |
Correct |
0 ms |
348 KB |
Output is correct |
16 |
Correct |
1 ms |
348 KB |
Output is correct |
17 |
Correct |
137 ms |
1008 KB |
Output is correct |
18 |
Correct |
2 ms |
604 KB |
Output is correct |
19 |
Correct |
29 ms |
672 KB |
Output is correct |
20 |
Correct |
1 ms |
348 KB |
Output is correct |
21 |
Correct |
179 ms |
1112 KB |
Output is correct |
22 |
Correct |
20 ms |
604 KB |
Output is correct |
23 |
Correct |
2 ms |
600 KB |
Output is correct |
24 |
Correct |
38 ms |
732 KB |
Output is correct |
25 |
Correct |
26 ms |
792 KB |
Output is correct |
26 |
Correct |
52 ms |
848 KB |
Output is correct |
27 |
Correct |
285 ms |
1340 KB |
Output is correct |
28 |
Correct |
258 ms |
1168 KB |
Output is correct |
29 |
Correct |
262 ms |
1288 KB |
Output is correct |
30 |
Correct |
263 ms |
1364 KB |
Output is correct |
31 |
Correct |
264 ms |
1768 KB |
Output is correct |
32 |
Correct |
264 ms |
1212 KB |
Output is correct |
33 |
Correct |
266 ms |
1364 KB |
Output is correct |
34 |
Correct |
276 ms |
1184 KB |
Output is correct |
35 |
Correct |
281 ms |
1232 KB |
Output is correct |
36 |
Correct |
276 ms |
1368 KB |
Output is correct |
37 |
Correct |
276 ms |
1292 KB |
Output is correct |