#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define fast ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
#define MOD 998244353
#define INF 1e18
#define fi first
#define se second
#define endl "\n"
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define FORD(i,a,b) for(int i=a;i>=b;i--)
#define sz(a) ((int)(a).size())
#define pi 3.14159265359
#define TASKNAME "amusepark"
template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }
using namespace std;
typedef pair<int,int> ii;
typedef pair<int,ii> iii;
typedef vector<int> vi;
const int MAXN = 3e2 + 9;
ii edge[MAXN];
int n,m,ans=0;
int degree[MAXN];
vector<int> g[MAXN];
bool visited[MAXN];
queue<int> q;
bool check(){
for(int i=1;i<=n;i++){
degree[i] = 0;
g[i].clear();
}
for(int i=1;i<=m;i++){
g[edge[i].fi].pb(edge[i].se);
degree[edge[i].se]++;
// cout<<edge[i].fi<<' '<<edge[i].se<<endl;
}
int cnt = 0;
// cout<<endl<<endl;
for(int i=1;i<=n;i++){
if (degree[i] == 0) q.push(i);
}
while(!q.empty()){
int u = q.front();
cnt++;
q.pop();
for(auto v: g[u]){
degree[v]--;
if (degree[v] == 0) q.push(v);
}
}
return cnt == n;
}
void backtrack(int pos,int cost){
if (pos==m+1){
if (check()){
ans = (ans + cost)%MOD;
}
return;
}
swap(edge[pos].fi,edge[pos].se);
backtrack(pos+1,cost+1);
swap(edge[pos].fi,edge[pos].se);
backtrack(pos+1,cost);
}
main()
{
fast;
// freopen(TASKNAME".inp","r",stdin);
// freopen(TASKNAME".out","w",stdout);
cin>>n>>m;
for(int i=1;i<=m;i++){
cin>>edge[i].fi>>edge[i].se;
}
backtrack(1,0);
cout<<ans<<endl;
}
Compilation message
amusementpark.cpp:69:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
69 | main()
| ^~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
600 KB |
Output is correct |
2 |
Correct |
1 ms |
344 KB |
Output is correct |
3 |
Correct |
0 ms |
344 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
344 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
600 KB |
Output is correct |
2 |
Correct |
1 ms |
344 KB |
Output is correct |
3 |
Correct |
0 ms |
344 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
344 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
0 ms |
348 KB |
Output is correct |
11 |
Correct |
0 ms |
348 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 |
Correct |
0 ms |
348 KB |
Output is correct |
16 |
Correct |
0 ms |
348 KB |
Output is correct |
17 |
Correct |
1 ms |
348 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
1 ms |
600 KB |
Output is correct |
20 |
Correct |
0 ms |
348 KB |
Output is correct |
21 |
Correct |
0 ms |
348 KB |
Output is correct |
22 |
Correct |
1 ms |
348 KB |
Output is correct |
23 |
Correct |
1 ms |
348 KB |
Output is correct |
24 |
Correct |
2 ms |
348 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
600 KB |
Output is correct |
2 |
Correct |
1 ms |
344 KB |
Output is correct |
3 |
Correct |
0 ms |
344 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
344 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
0 ms |
348 KB |
Output is correct |
11 |
Correct |
0 ms |
348 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 |
Correct |
0 ms |
348 KB |
Output is correct |
16 |
Correct |
0 ms |
348 KB |
Output is correct |
17 |
Correct |
1 ms |
348 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
1 ms |
600 KB |
Output is correct |
20 |
Correct |
0 ms |
348 KB |
Output is correct |
21 |
Correct |
0 ms |
348 KB |
Output is correct |
22 |
Correct |
1 ms |
348 KB |
Output is correct |
23 |
Correct |
1 ms |
348 KB |
Output is correct |
24 |
Correct |
2 ms |
348 KB |
Output is correct |
25 |
Correct |
0 ms |
344 KB |
Output is correct |
26 |
Correct |
0 ms |
348 KB |
Output is correct |
27 |
Correct |
0 ms |
348 KB |
Output is correct |
28 |
Correct |
1 ms |
348 KB |
Output is correct |
29 |
Correct |
2 ms |
344 KB |
Output is correct |
30 |
Correct |
16 ms |
348 KB |
Output is correct |
31 |
Correct |
134 ms |
348 KB |
Output is correct |
32 |
Correct |
0 ms |
348 KB |
Output is correct |
33 |
Correct |
0 ms |
348 KB |
Output is correct |
34 |
Correct |
1 ms |
348 KB |
Output is correct |
35 |
Correct |
5 ms |
348 KB |
Output is correct |
36 |
Correct |
71 ms |
440 KB |
Output is correct |
37 |
Correct |
1248 ms |
444 KB |
Output is correct |
38 |
Execution timed out |
3060 ms |
348 KB |
Time limit exceeded |
39 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
600 KB |
Output is correct |
2 |
Correct |
1 ms |
344 KB |
Output is correct |
3 |
Correct |
0 ms |
344 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
344 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
0 ms |
348 KB |
Output is correct |
11 |
Correct |
0 ms |
348 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 |
Correct |
0 ms |
348 KB |
Output is correct |
16 |
Correct |
0 ms |
348 KB |
Output is correct |
17 |
Correct |
1 ms |
348 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
1 ms |
600 KB |
Output is correct |
20 |
Correct |
0 ms |
348 KB |
Output is correct |
21 |
Correct |
0 ms |
348 KB |
Output is correct |
22 |
Correct |
1 ms |
348 KB |
Output is correct |
23 |
Correct |
1 ms |
348 KB |
Output is correct |
24 |
Correct |
2 ms |
348 KB |
Output is correct |
25 |
Correct |
0 ms |
344 KB |
Output is correct |
26 |
Correct |
0 ms |
348 KB |
Output is correct |
27 |
Correct |
0 ms |
348 KB |
Output is correct |
28 |
Correct |
1 ms |
348 KB |
Output is correct |
29 |
Correct |
2 ms |
344 KB |
Output is correct |
30 |
Correct |
16 ms |
348 KB |
Output is correct |
31 |
Correct |
134 ms |
348 KB |
Output is correct |
32 |
Correct |
0 ms |
348 KB |
Output is correct |
33 |
Correct |
0 ms |
348 KB |
Output is correct |
34 |
Correct |
1 ms |
348 KB |
Output is correct |
35 |
Correct |
5 ms |
348 KB |
Output is correct |
36 |
Correct |
71 ms |
440 KB |
Output is correct |
37 |
Correct |
1248 ms |
444 KB |
Output is correct |
38 |
Execution timed out |
3060 ms |
348 KB |
Time limit exceeded |
39 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
600 KB |
Output is correct |
2 |
Correct |
1 ms |
344 KB |
Output is correct |
3 |
Correct |
0 ms |
344 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
344 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
0 ms |
348 KB |
Output is correct |
11 |
Correct |
0 ms |
348 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 |
Correct |
0 ms |
348 KB |
Output is correct |
16 |
Correct |
0 ms |
348 KB |
Output is correct |
17 |
Correct |
1 ms |
348 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
1 ms |
600 KB |
Output is correct |
20 |
Correct |
0 ms |
348 KB |
Output is correct |
21 |
Correct |
0 ms |
348 KB |
Output is correct |
22 |
Correct |
1 ms |
348 KB |
Output is correct |
23 |
Correct |
1 ms |
348 KB |
Output is correct |
24 |
Correct |
2 ms |
348 KB |
Output is correct |
25 |
Correct |
0 ms |
344 KB |
Output is correct |
26 |
Correct |
0 ms |
348 KB |
Output is correct |
27 |
Correct |
0 ms |
348 KB |
Output is correct |
28 |
Correct |
1 ms |
348 KB |
Output is correct |
29 |
Correct |
2 ms |
344 KB |
Output is correct |
30 |
Correct |
16 ms |
348 KB |
Output is correct |
31 |
Correct |
134 ms |
348 KB |
Output is correct |
32 |
Correct |
0 ms |
348 KB |
Output is correct |
33 |
Correct |
0 ms |
348 KB |
Output is correct |
34 |
Correct |
1 ms |
348 KB |
Output is correct |
35 |
Correct |
5 ms |
348 KB |
Output is correct |
36 |
Correct |
71 ms |
440 KB |
Output is correct |
37 |
Correct |
1248 ms |
444 KB |
Output is correct |
38 |
Execution timed out |
3060 ms |
348 KB |
Time limit exceeded |
39 |
Halted |
0 ms |
0 KB |
- |