Submission #983388

#	Time	Username	Problem	Language	Result	Execution time	Memory
983388		duckindog	Amusement Park (CEOI19_amusementpark)	C++17	19 / 100	7 ms	1464 KiB

amusementpark

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

const int N = 18 + 10,
          M = 998'244'353;
int n, m;
int a[N], b[N];

int32_t main() { 
  cin.tie(0)->sync_with_stdio(0);
 
  cin >> n >> m;
  for (int i = 1; i <= m; ++i) cin >> a[i] >> b[i];
 
  long long answer = 0;
  vector<int> vt(n); iota(vt.begin(), vt.end(), 1);
  unordered_map<long long, bool> mk;
  
  do { 
    vector<int> p(n + 1);  
    for (int i = 0; i < n; ++i) p[vt[i]] = i;
    long long mask = 0;
    for (int i = 1; i <= m; ++i) if (p[a[i]] > p[b[i]]) mask |= (1 << i - 1);
    if (!mk[mask]) answer += __builtin_popcount(mask);
    mk[mask] = true;
  } while (next_permutation(vt.begin(), vt.end()));
  
  cout << answer % M << "\n";
}

Compilation message (stderr)

amusementpark.cpp: In function 'int32_t main()':
amusementpark.cpp:24:73: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   24 |     for (int i = 1; i <= m; ++i) if (p[a[i]] > p[b[i]]) mask |= (1 << i - 1);
      |                                                                       ~~^~~

• Subtask 1: 7 / 7
• Subtask 2: 12 / 12
• Subtask 3: 0 / 23
• Subtask 4: 0 / 21
• Subtask 5: 0 / 37