Submission #1062538

#	Time	Username	Problem	Language	Result	Execution time	Memory
1062538		sleepntsheep	Amusement Park (CEOI19_amusementpark)	C++17	42 / 100	3057 ms	162008 KiB

amusementpark

#include <stdio.h>
#include <algorithm>
#include <unordered_set>

using namespace std;
using ll = long long;

int n, m, a[999], b[999], p[22], q[22];

int main() {
  scanf("%d%d", &n, &m);
  for (int i = 0; i < m; ++i)
    scanf("%d%d", a+i, b+i), --a[i], --b[i];

  ll ans {};

  unordered_set<ll> vis;
  for (int i = 0; i < n; ++i) p[i] = i;
  do {
    for (int j = 0; j < n; ++j) q[p[j]] = j;
    ll z {}, y {};
    for (int i = 0; i < m; ++i) {
      if (q[a[i]] < q[b[i]]) z |= 1ll << i, ++y;
    }
    if (not vis.count(z)) vis.insert(z), ans += y;
  } while (next_permutation(p, p + n));

  printf("%lld", ans % 998244353);
}

Compilation message (stderr)

amusementpark.cpp: In function 'int main()':
amusementpark.cpp:11:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |   scanf("%d%d", &n, &m);
      |   ~~~~~^~~~~~~~~~~~~~~~
amusementpark.cpp:13:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |     scanf("%d%d", a+i, b+i), --a[i], --b[i];
      |     ~~~~~^~~~~~~~~~~~~~~~~~

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