#include "bits/stdc++.h"
using namespace std;
#define endl '\n'
#define debug(x) cerr << #x << " == " << (x) << '\n';
#define all(x) begin(x), end(x)
using ll = long long;
const int INF = 0x3f3f3f3f;
const ll LINF = 0x3f3f3f3f3f3f3f3fLL;
template<ll mod>
struct Mint {
ll x;
Mint(ll x = 0) : x((x %= mod) < 0 ? x + mod : x) { }
Mint& operator+=(Mint rhs) { return (x += rhs.x) >= mod ? x -= mod : 0, *this; }
Mint& operator-=(Mint rhs) { return (x -= rhs.x) < 0 ? x += mod : 0, *this; }
Mint& operator*=(Mint rhs) { return (x *= rhs.x) %= mod, *this; }
Mint& operator/=(Mint rhs) { return *this *= rhs.power(-1); }
Mint power(ll p) const {
p %= mod - 1;
if (p < 0) p += mod - 1;
Mint res = 1;
for (Mint y = *this; p; p >>= 1, y *= y) if (p & 1) res *= y;
return res;
}
bool operator==(Mint rhs) const { return x == rhs.x; }
bool operator<(Mint rhs) const { return x < rhs.x; }
friend Mint operator+(Mint lhs, Mint rhs) { return lhs += rhs; }
friend Mint operator-(Mint lhs, Mint rhs) { return lhs -= rhs; }
friend Mint operator*(Mint lhs, Mint rhs) { return lhs *= rhs; }
friend Mint operator/(Mint lhs, Mint rhs) { return lhs /= rhs; }
friend ostream& operator<<(ostream& out, Mint a) { return out << a.x; }
friend istream& operator>>(istream& in, Mint& a) {
ll x;
in >> x;
a = Mint(x);
return in;
}
};
constexpr ll mod = 998244353;
using mint = Mint<mod>;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
int n, m;
cin >> n >> m;
vector<int> E(n);
for (int j = 0; j < m; ++j) {
int u, v;
cin >> u >> v;
--u, --v;
E[u] |= 1 << v;
}
vector<int> popcount(1 << n);
for (int mask = 1; mask < (1 << n); ++mask) {
popcount[mask] = 1 + popcount[mask & (mask - 1)];
}
vector<mint> sum(1 << n), cnt(1 << n);
cnt[0] = 1;
for (int mask = 0; mask < (1 << n); ++mask) {
for (int u = 0; u < n; ++u) {
if (mask >> u & 1) continue;
int nmask = mask | 1 << u;
cnt[nmask] += cnt[mask];
sum[nmask] += sum[mask] + cnt[mask] * popcount[E[u] & mask];
}
}
mint ans = sum.back();
cout << ans << endl;
exit(0);
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
204 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
204 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
204 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
204 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
204 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |