Submission #1251762

#	Time	Username	Problem	Language	Result	Execution time	Memory
1251762		chikien2009	Calvinball championship (CEOI15_teams)	C++20	100 / 100	146 ms	752 KiB

teams

#include <bits/stdc++.h>

using namespace std;

void setup()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

const long long mod = 1000007;
long long n, f[10002], g[10002], a[10002], p[10002], res = 1;

int main()
{
    setup();

    cin >> n;
    for (long long i = 1; i <= n; ++i)
    {
        cin >> a[i];
        p[i] = max(p[i - 1], a[i]);
    }
    reverse(a + 1, a + 1 + n);
    reverse(p + 1, p + 1 + n);
    fill_n(f, n + 2, 1);
    // f[i] is the number of team selection available if the maximum a[i] in the prefix is i
    for (long long i = 1; i <= n; ++i)
    {
        for (long long j = 1; j <= n; ++j)
        {
            g[j] = (f[j] * j + f[j + 1]) % mod;
        }
        (res += (a[i] - 1) * f[p[i + 1]]) %= mod;
        for (long long j = 1; j <= n; ++j)
        {
            f[j] = g[j];
        }
    }
    cout << res;
    return 0;
}

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