Submission #753011

#	Time	Username	Problem	Language	Result	Execution time	Memory
753011		Ronin13	Calvinball championship (CEOI15_teams)	C++14	80 / 100	1059 ms	976 KiB

teams

#include <bits/stdc++.h>
#define ll long long
#define f first
#define s second
#define pll pair<ll,ll>
#define pb push_back
#define epb emplace_back
#define ull unsigned ll
#define pii pair<int,int>
using namespace std;
const int nmax = 10001;
ll mod = 1e6 + 7;

ll dp[nmax];
ll DP[nmax];

ll c[nmax];

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0);
    int n; cin >> n;
    //fil(2);
    int a[n + 1];
    for(int i = 1; i <= n; i++){
        cin >> a[i];
    }
    dp[0] = 1;
    DP[0] = 1;
    c[0] = 1;
    for(int i = 1; i <= n ;i++){
        for(int j = i; j >= 1 ;j--){
            dp[j] = (ll)dp[j - 1] + (ll)dp[j] * (ll)j;
            DP[i] += dp[j];
            DP[i] %= mod;
            dp[j] %= mod;
        }
        dp[0] = 0;
       // cout << DP[i] << ' ';
    }
    set <int> st;
    ll po[n + 1];
    ll ans = 1;
    ll val[n + 1];
    val[1] = 1;
    st.insert(a[1]);
    for(int i = 2; i <= n; i++){
        st.insert(a[i]);
        val[i] = st.size();
    }
    for(int i = n ;i >= 2; --i){
        c[n - i] = 1;
        for(int j = n - i - 1; j >= 1 ;j--)
            c[j] += c[j - 1], c[j] %= mod;
        if(i != 1){
            ll P = 1;
            ll res = 0;
            for(int x = n - i; x >= 0; x--){
                res += c[x] * DP[x] * P;
                res %= mod;
                P *= val[i - 1];
                P %= mod;
            }
            res *= (ll)(a[i] - 1);
            res %= mod;
            ans += res;
            ans %= mod;
        }

    }
    cout << ans;
}

Compilation message (stderr)

teams.cpp: In function 'int main()':
teams.cpp:41:8: warning: unused variable 'po' [-Wunused-variable]
   41 |     ll po[n + 1];
      |        ^~

• 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: 0 / 10
• Subtask 9: 10 / 10
• Subtask 10: 0 / 10