Submission #679885

#	Time	Username	Problem	Language	Result	Execution time	Memory
679885		peijar	Calvinball championship (CEOI15_teams)	C++17	100 / 100	368 ms	676 KiB

teams

#include <bits/stdc++.h>
#define int long long
using namespace std;

namespace std {
template <typename T> ostream &operator<<(ostream &out, const vector<T> &vec) {
  out << "[";
  for (int i = 0; i < (int)vec.size(); ++i) {
    out << vec[i];
    if (i + 1 < (int)vec.size())
      out << ", ";
  }
  return out << "]";
}
} // namespace std

void dbg_out() { cout << endl; }
template <typename Head, typename... Tail> void dbg_out(Head H, Tail... T) {
  cout << ' ' << H;
  dbg_out(T...);
}

#ifdef DEBUG
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif

const int MOD = 1e6 + 7;

const int MAXN = 1e4 + 1;

int fact[MAXN];
int DP[2][MAXN];

void init() {
  fact[0] = 1;
  for (int i = 1; i < MAXN; i++)
    fact[i] = i * fact[i - 1] % MOD;
}

signed main(void) {
  ios_base::sync_with_stdio(false);
  cin.tie(0);

  int n;
  cin >> n;
  vector<int> a(n);
  for (int &x : a) {
    cin >> x;
  }

  int ret = 0;
  vector<int> prefMax(n + 1);
  for (int i = 1; i < n; ++i)
    prefMax[i + 1] = max(prefMax[i], a[i]);
  for (int i = 1; i <= n; ++i)
    DP[0][i] = 1;
  for (int i = n - 1; i >= 1; --i) {
    int maxVu = prefMax[i];
    int restant = n - i - 1;
    for (int val = 1; val < a[i]; ++val) {
      ret += DP[restant % 2][max(val, maxVu)];
      dbg(i, val, ret);
      if (ret >= MOD)
        ret -= MOD;
    }
    int p = (restant + 1) % 2;
    for (int vu = 1; vu <= n; ++vu) {
      DP[p][vu] = vu * DP[!p][vu] % MOD;
      if (vu < n) {
        DP[p][vu] += DP[!p][vu + 1];
        if (DP[p][vu] >= MOD)
          DP[p][vu] -= MOD;
      }
    }
  }
  cout << ret + 1 << endl;
}

• 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