Submission #19491

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
19491	2016-02-24T14:10:07 Z	kaTkaHr	악수 (kriii4_D)	C++14	5 / 100	3000 ms	34544 KB

D

#include <stdio.h>
#include<vector>
#include <algorithm>
#include <map>

using namespace std;

typedef long long ll;

const int MX = 45, MM = 1000000007;

template<typename T>
T pw(T A, ll B){
  T R = 1;
  while(B){
    if( B&1 ) R = R * A;
    A = A * A; B /= 2;
  }
  return R;
}

ll rv(ll A){ 
  ll R = 1, B = MM-2;
  while(B){
    if( B&1 ) R = R * A % MM;
    A = A * A % MM; B /= 2;
  }
  return R;
}
/*
struct frac{
  ll A, B;
		frac(ll A):A(A), B(1){}
  frac(ll a, ll b){
    A = (a%MM+MM) % MM;
    B = (b%MM+MM) % MM;
  }
  frac(){A = 0, B = 1;}
  frac operator+ (const frac &l)const{
    return frac((A * l.B + B * l.A) % MM, B * l.B % MM);
  }
  frac operator*(const frac &l)const{
    return frac(A*l.A % MM, B*l.B % MM);
  }
  frac operator/(const frac &l)const{
    return frac(A*l.B % MM, B*l.A % MM);
  }
  frac operator- (const frac &l)const{
    return frac((A*l.B - B*l.A%MM + MM) % MM, B*l.B % MM);
  }
  ll v(){ return A * rv(B) % MM; }
};// */
//*
struct frac{
  ll A;
		frac(ll A):A((A%MM+MM)%MM){}
  frac(ll a, ll b){
			a = (a%MM+MM)%MM;
			b = (b%MM+MM)%MM;
			A = rv(b) * a % MM;
  }
  frac(){A = 0;}
  frac operator+ (const frac &l)const{
			return l.A + A >= MM? l.A + A - MM: l.A + A;
  }
  frac operator*(const frac &l)const{
			return l.A * A % MM;
  }
  frac operator/(const frac &l)const{
			return A * rv(l.A) % MM;
  }
  frac operator- (const frac &l)const{
			return A >= l.A? A-l.A: A-l.A + MM;
  }
  ll v(){ return A; }
};// */

frac D[MX][MX*MX], E[MX][MX*MX], C[MX*MX][MX*MX];

int main()
{
	int N, T;
	scanf("%d", &N); T = N*(N-1) / 2;

	C[0][0] = 1;
	for(int i = 1; i <= T || i <= N; i++){
		C[i][0] = 1;
		for(int j = 1; j <= i; j++){
			C[i][j] = C[i-1][j-1] + C[i-1][j];
		}
	}

	D[1][0] = E[1][0] = 1;
	for(int i = 2; i <= N; i++){
		for(int x = i-1; x <= i*(i-1)/2; x++){
			for(int k = 1; k <= i-1; k++){
				for(int l = 0; l <= x-1; l++){
					E[i][x] = E[i][x] + D[k][l] * D[i-k][x-l-1] * frac(k*(i-k), 1) * C[i-1][k-1] * C[x-1][l];
				}
			}
			D[i][x] = D[i][x-1] * frac(i*(i-1)/2 - x + 1, 1) + E[i][x];
		}
	}
	frac ans = 0, mul = 1;
	frac tot = 0;
	for(int i = 0; i <= T; i++){
		tot = tot + E[N][i] * mul;
		ans = ans + E[N][i] * i * mul;
		mul = mul * frac(1, T-i);
	}
	printf("%lld\n", ans.v());
}

Subtask #1

5.0 / 5.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	8 ms	34544 KB	Output is correct
2	Correct	4 ms	34544 KB	Output is correct
3	Correct	4 ms	34544 KB	Output is correct
4	Correct	4 ms	34544 KB	Output is correct
5	Correct	8 ms	34544 KB	Output is correct

Subtask #2

0.0 / 95.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	34544 KB	Output is correct
2	Correct	4 ms	34544 KB	Output is correct
3	Correct	4 ms	34544 KB	Output is correct
4	Correct	4 ms	34544 KB	Output is correct
5	Correct	9 ms	34544 KB	Output is correct
6	Correct	7 ms	34544 KB	Output is correct
7	Correct	8 ms	34544 KB	Output is correct
8	Correct	7 ms	34544 KB	Output is correct
9	Correct	7 ms	34544 KB	Output is correct
10	Correct	16 ms	34544 KB	Output is correct
11	Correct	24 ms	34544 KB	Output is correct
12	Correct	39 ms	34544 KB	Output is correct
13	Correct	49 ms	34544 KB	Output is correct
14	Correct	68 ms	34544 KB	Output is correct
15	Correct	96 ms	34544 KB	Output is correct
16	Correct	124 ms	34544 KB	Output is correct
17	Correct	165 ms	34544 KB	Output is correct
18	Correct	220 ms	34544 KB	Output is correct
19	Correct	285 ms	34544 KB	Output is correct
20	Correct	359 ms	34544 KB	Output is correct
21	Correct	449 ms	34544 KB	Output is correct
22	Correct	569 ms	34544 KB	Output is correct
23	Correct	708 ms	34544 KB	Output is correct
24	Correct	872 ms	34544 KB	Output is correct
25	Correct	1065 ms	34544 KB	Output is correct
26	Correct	1298 ms	34544 KB	Output is correct
27	Correct	1585 ms	34544 KB	Output is correct
28	Correct	1895 ms	34544 KB	Output is correct
29	Correct	2262 ms	34544 KB	Output is correct
30	Correct	2704 ms	34544 KB	Output is correct
31	Execution timed out	3000 ms	34544 KB	Program timed out
32	Halted	0 ms	0 KB	-