Submission #19264

#	TimeUTC-0	Username	Problem	Language	Result	Execution time	Memory
19264	2016-02-23 14:05:41	kriii	악수 (kriii4_D)	C++14	100 / 100	1238 ms	6600 KiB

D

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#include <stdio.h>
const long long mod = 1000000007;
long long inv[800],comb[800][800],end[41][800],all[41][800];
int main()
{
  int n,m; scanf ("%d",&n);
  comb[0][0] = comb[1][0] = comb[1][1] = inv[1] = 1;
  for (int i=2;i<800;i++){
    comb[i][0] = comb[i][i] = 1;
    for (int j=1;j<i;j++) comb[i][j] = (comb[i-1][j-1] + comb[i-1][j]) % mod;
    inv[i] = (mod - mod / i) * inv[mod % i] % mod;
  }
  end[1][0] = all[1][0] = 1;
  for (int v=2;v<=n;v++){
    int l = v * (v - 1) / 2;
    for (int e=v-1;e<=l;e++){
      for (int i=0;i<v-1;i++) for (int j=0;j<e;j++){
        long long add = comb[v-1][i] * comb[e-1][j] % mod;
        add = add * all[i+1][j] % mod;
        add = add * all[v-i-1][e-j-1] % mod;
        add = add * (i + 1) * (v - i - 1) % mod;
        end[v][e] += add;
      }
      end[v][e] %= mod;
      all[v][e] = (end[v][e] + (l - e + 1) * all[v][e-1]) % mod;
    }
  }
 
 
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• Subtask 1: 5 / 5
• Subtask 2: 95 / 95