Submission #69073

#	Time	Username	Problem	Language	Result	Execution time	Memory
69073		Bodo171	Calvinball championship (CEOI15_teams)	C++14	0 / 100	4 ms	680 KiB

teams

#include <iostream>
#include <fstream>
using namespace std;
const int nmax=10005;
const long long mod=1000*1000+7;
long long c[2][nmax],bell[nmax],mx[nmax],pw[nmax];
long long ans;
int v[nmax];
int n,i,j,use;
int main()
{
    freopen("data.in","r",stdin);
    cin>>n;
    for(i=1;i<=n;i++)
    {
        cin>>v[i];
        mx[i]=max(mx[i-1],1LL*v[i]);
    }
    bell[0]=1;
    ans=v[n]-1;c[0][0]=1;
    for(i=1;i<n;i++)
    {
        use=1-use;
        c[use][0]=1;
        for(j=1;j<=i;j++)
        {
            c[use][j]=(c[1-use][j]+c[1-use][j-1])%mod;
        }
        if(i==1)
            c[use][1]=1;
        pw[0]=v[n-i]-1;
        for(j=1;j<=i;j++)
            pw[j]=(1LL*pw[j-1]*mx[n-i-1])%mod;
        for(j=0;j<i;j++)
        {
            bell[i]=(1LL*bell[i]+(bell[j]*c[1-use][j]))%mod;
        }
        for(j=1;j<=i;j++)
            ans=(ans+1LL*bell[i-j]*c[use][j]*pw[j])%mod;
        ans=(ans+bell[i]*pw[0])%mod;
    }
    cout<<(ans+1)%mod;
    return 0;
}

Compilation message (stderr)

teams.cpp: In function 'int main()':
teams.cpp:12:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     freopen("data.in","r",stdin);
     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~

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