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Submission #146741

# Submission time Handle Problem Language Result Execution time Memory
146741 2019-08-25T19:25:36 Z vex Calvinball championship (CEOI15_teams) C++14
100 / 100
 133 ms 732 KB 
#include<bits/stdc++.h>
#define maxn 10005
#define mod 1000007
#define ll long long
using namespace std;

int n;
int a[maxn];
ll dp[2][maxn];
int g[maxn];

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    cin>>n;
    for(int i=1;i<=n;i++)cin>>a[i];
    g[1]=1;
    for(int i=2;i<=n;i++)g[i]=max(g[i-1],a[i]);

    /*for(int d=1;d<n;d++)
    {
        for(int k=1;k+d<=n;k++)
        {
            if(d==1)dp[d][k]=k+1;
            else
            {
                dp[d][k]=dp[d-1][k+1]+k*dp[d-1][k];
                dp[d][k]%=mod;
            }
        }
    }*/

    /*for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=n;j++)
        {
            cout<<dp[i][j]<<" ";
        }
        cout<<endl;
    }*/

    int prev=0;
    int curr=1;

    long long ans=0;
    for(int i=n;i>=2;i--)
    {
        if(i!=n)
        {
            int d=n-i;
            for(int k=1;k+d<=n;k++)
            {
                if(d==1)dp[curr][k]=k+1;
                else
                {
                    dp[curr][k]=dp[prev][k+1]+k*dp[prev][k];
                    dp[curr][k]%=mod;
                }
            }
        }


        ll br;
        if(i==n)
        {
            br=1;
        }
        else if(g[i]==g[i-1])
        {
            br=dp[curr][g[i]];
        }
        else
        {
            br=dp[curr][g[i]-1];
        }




        ans+=(a[i]-1)*br;
        ans%=mod;

        swap(curr,prev);
    }

    cout<<(ans+1)%mod<<endl;
    return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 380 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 380 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 504 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB Output is correct
2 Correct 3 ms 376 KB Output is correct
3 Correct 3 ms 376 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 123 ms 676 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 33 ms 504 KB Output is correct
2 Correct 33 ms 504 KB Output is correct
3 Correct 34 ms 540 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 126 ms 664 KB Output is correct
2 Correct 127 ms 640 KB Output is correct
3 Correct 133 ms 732 KB Output is correct