Submission #290380

#	Time	Username	Problem	Language	Result	Execution time	Memory
290380		Hehehe	Calvinball championship (CEOI15_teams)	C++14	100 / 100	402 ms	632 KiB

teams

#include<bits/stdc++.h> //:3
using namespace std;
typedef long long ll;
#define all(a) (a).begin(), (a).end()
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define pi pair<int, int>
#define sz(x) (int)((x).size())
//#define int long long

const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};

const ll inf = 2e9;
const ll mod = 1e6 + 7;
const int N = 1e4 + 11;
const int X = 1e6;
const ll INF64 = 3e18 + 1;
const double eps = 1e-14;
const double PI = acos(-1);

//ifstream in(".in");
//ofstream out(".out");

int n, a[N], dp[2][N], mx[N];

void solve(){

    cin >> n;

    for(int i = 1; i <= n; i++){
        cin >> a[i];
        mx[i] = max(mx[i - 1], a[i]);
    }

    //dp[i][j] - ways of choosing i more elements having j as the maximum element in our subsequence

    for(int i = 0; i <= n; i++){
        dp[0][i] = 1; //one way of adding 0 elements
    }

    int ans = a[n] * 1ll, t = 1;

    for(int i = 1; i < n; i++){
            
        for(int j = 1; j <= n; j++)
            dp[t][j] = (dp[1 - t][j + 1] + 1LL * dp[1 - t][j] * j % mod) % mod;
 
        ans = (ans + 1LL * dp[t][mx[n - i - 1]] * (a[n - i] - 1) % mod) % mod;
        
        t = 1 - t;
    }

    cout << (ans + mod) % mod << '\n';
}

int32_t main(){
ios_base :: sync_with_stdio(0); cin.tie(0); cout.tie(0);

    //cout << setprecision(6) << fixed;

    int T = 1;
    //cin >> T;
    while(T--){
        solve();
    }
}

• 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