제출 #89385

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
89385		sjhuang26	Calvinball championship (CEOI15_teams)	C++14	20 / 100	112 ms	1012 KiB

teams

#include<iostream>
using namespace std;
int a[10000],N,x[10000];
typedef long long ll;
ll d[2][10001];//given at nth position (implicit, reverse) and cutoff index (starts at 0): # of possibilities?
const int md=1e9+7,ans=0;
int main(){
  cin>>N;
  for(int i=0;i<N;++i)cin>>a[i];
  int u=0,ans=0;
  for(int i=0;i<N;++i){
    x[i]=u=max(u,a[i]);
  }
  for(int i=0;i<=N;++i){
    d[N%2][i]=1;
  }
  for(int i=N-1;i>=0;--i){
    for(int j=0;j<=i;++j){
      d[i%2][j]=(d[(i+1)%2][j+1]+d[(i+1)%2][j]*j)%md;
    }
    if(i==N-1){
      ans+=(d[i%2][a[i]-1]);
    }else{
      ans+=(d[(i+1)%2][x[i]-1]*(a[i]-1));
    }
    ans%=md;
    //cout<<ans<<endl;
  }
  cout<<ans<<'\n';
  return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10