Submission #476139

#	Time	Username	Problem	Language	Result	Execution time	Memory
476139		tmbao	Calvinball championship (CEOI15_teams)	C++14	100 / 100	118 ms	532 KiB

teams

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

const int mod = 1000007;

int main() {
  // Input
  int n;
  cin >> n;
  vector<int> a;
  for (int i = 0; i < n; ++i) {
    int x;
    cin >> x;
    a.push_back(x);
  }

  // Solve
  vector<vector<long long>> dp;
  dp.resize(2);
  dp[0].resize(n + 1);
  dp[1].resize(n + 1);

  for (int i = 0, maxA = 0; i < n; ++i) {
    maxA = max(maxA, a[i] - 1);
    int currentI = i & 1;
    int previousI = currentI ^ 1;
    for (int j = 1; j <= i + 1; ++j) {
      dp[currentI][j] = (dp[previousI][j] * j + dp[previousI][j - 1]) % mod;
      if (j == maxA) {
        dp[currentI][j] = (dp[currentI][j] + a[i] - 1) % mod;
      }
    }
    maxA = max(maxA, a[i]);
  }

  long long ans = 1;
  for (int i = 1; i <= n; ++i) {
    ans = (ans + dp[n & 1 ^ 1][i]) % mod;
  }
  cout << ans;

  return 0;
}

Compilation message (stderr)

teams.cpp: In function 'int main()':
teams.cpp:38:23: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   38 |     ans = (ans + dp[n & 1 ^ 1][i]) % mod;
      |                     ~~^~~

• 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