#include <bits/stdc++.h>
using namespace std;
#define int long long
#define arr array
#define vct vector
const int MX_N = 18 + 2, MD = 998244353;
int n, m;
arr<arr<bool, MX_N>, MX_N> adj;
int md(int x) { return (x + MD) % MD; }
int expn(int x, int y) {
if (y == 0) return 1;
int ans = expn(x, y / 2);
ans = md(ans * ans);
if (y % 2 == 1) ans = md(ans * x);
return ans;
}
int inv(int x) { return expn(x, MD - 2); }
arr<bool, 1 << MX_N> indp;
arr<int, 1 << MX_N> mltp;
void prcmp() {
indp[0] = true;
for (int msk = 1; msk < (1 << n); msk++) {
for (int u = 1; u <= n; u++) {
if (!(msk & (1 << (u - 1)))) continue;
indp[msk] = indp[msk ^ (1 << (u - 1))];
for (int v = 1; v <= n; v++) {
if (!(msk & (1 << (v - 1)))) continue;
if (v == u) continue;
if (adj[u][v]) indp[msk] = false;
}
break;
}
}
for (int msk = 0; msk < (1 << n); msk++) {
int sz = 0;
for (int u = 1; u <= n; u++) sz += (bool) (msk & (1 << (u - 1)));
mltp[msk] = (sz % 2 == 1) ? 1 : -1;
}
}
arr<int, MX_N> dp;
void cmp() {
dp[0] = 1;
for (int msk = 1; msk < (1 << n); msk++)
for (int sb_msk = msk; sb_msk != 0; sb_msk = (sb_msk - 1) & msk)
if (indp[sb_msk]) dp[msk] = md(dp[msk] + md(mltp[sb_msk] * dp[msk ^ sb_msk]));
}
signed main() {
// freopen("prk.in", "r", stdin);
cin >> n >> m;
for (int i = 1; i <= m; i++) {
int u, v; cin >> u >> v;
adj[u][v] = adj[v][u] = true;
}
prcmp();
cmp();
int ans = md(dp[(1 << n) - 1] * md(m * inv(2)));
cout << ans << endl;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Correct |
0 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
440 KB |
Output is correct |
| 7 |
Correct |
0 ms |
348 KB |
Output is correct |
| 8 |
Correct |
0 ms |
348 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Correct |
0 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
440 KB |
Output is correct |
| 7 |
Correct |
0 ms |
348 KB |
Output is correct |
| 8 |
Correct |
0 ms |
348 KB |
Output is correct |
| 9 |
Correct |
1 ms |
348 KB |
Output is correct |
| 10 |
Correct |
1 ms |
504 KB |
Output is correct |
| 11 |
Correct |
1 ms |
344 KB |
Output is correct |
| 12 |
Correct |
0 ms |
348 KB |
Output is correct |
| 13 |
Correct |
0 ms |
348 KB |
Output is correct |
| 14 |
Correct |
0 ms |
348 KB |
Output is correct |
| 15 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 16 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Correct |
0 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
440 KB |
Output is correct |
| 7 |
Correct |
0 ms |
348 KB |
Output is correct |
| 8 |
Correct |
0 ms |
348 KB |
Output is correct |
| 9 |
Correct |
1 ms |
348 KB |
Output is correct |
| 10 |
Correct |
1 ms |
504 KB |
Output is correct |
| 11 |
Correct |
1 ms |
344 KB |
Output is correct |
| 12 |
Correct |
0 ms |
348 KB |
Output is correct |
| 13 |
Correct |
0 ms |
348 KB |
Output is correct |
| 14 |
Correct |
0 ms |
348 KB |
Output is correct |
| 15 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 16 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Correct |
0 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
440 KB |
Output is correct |
| 7 |
Correct |
0 ms |
348 KB |
Output is correct |
| 8 |
Correct |
0 ms |
348 KB |
Output is correct |
| 9 |
Correct |
1 ms |
348 KB |
Output is correct |
| 10 |
Correct |
1 ms |
504 KB |
Output is correct |
| 11 |
Correct |
1 ms |
344 KB |
Output is correct |
| 12 |
Correct |
0 ms |
348 KB |
Output is correct |
| 13 |
Correct |
0 ms |
348 KB |
Output is correct |
| 14 |
Correct |
0 ms |
348 KB |
Output is correct |
| 15 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 16 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Correct |
0 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
440 KB |
Output is correct |
| 7 |
Correct |
0 ms |
348 KB |
Output is correct |
| 8 |
Correct |
0 ms |
348 KB |
Output is correct |
| 9 |
Correct |
1 ms |
348 KB |
Output is correct |
| 10 |
Correct |
1 ms |
504 KB |
Output is correct |
| 11 |
Correct |
1 ms |
344 KB |
Output is correct |
| 12 |
Correct |
0 ms |
348 KB |
Output is correct |
| 13 |
Correct |
0 ms |
348 KB |
Output is correct |
| 14 |
Correct |
0 ms |
348 KB |
Output is correct |
| 15 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 16 |
Halted |
0 ms |
0 KB |
- |
