Submission #873055

#	Time	Username	Problem	Language	Result	Execution time	Memory
873055		tvladm2009	Calvinball championship (CEOI15_teams)	C++17	100 / 100	170 ms	892 KiB

teams

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N = 1e4 + 7;
const int M = 1e6 + 7;

int a[N], kek[N], teams[N];

int add(int a, int b) {
    return a + b > M ? a + b - M : a + b;
}

int mul(int a, int b) {
    return a * 1ll * b % M;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    for (int i = 1; i <= n; ++i) {
        cin >> a[i];
        teams[i] = teams[i - 1] + (kek[a[i]] == 0);
        if (kek[a[i]] == 0) {
            kek[a[i]] = i;
        }
    }
    int ans = 0;
    vector<vector<int>> dp(2, vector<int>(n + 1, 1));
    for (int i = n; i >= 1; --i) {
        for (int k = 0; k <= i; ++k) {
            dp[0][k] = add(mul(dp[1][k], k), dp[1][k + 1]);
        }
        for (int x = 1; x < a[i]; ++x) {
            ans = add(ans, dp[1][teams[i - 1]] + (i < kek[x]));
        }
        swap(dp[0], dp[1]);
    }
    cout << add(ans, 1) << "\n";
    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