#include<bits/stdc++.h>
#define int long long
#define forn(i,n) for(int i = 0;i < n;i++)
#define Forn(i,n) for(int i = 1;i <= n;i++)
#define vi vector<int>
#define pb push_back
#define pii pair<int,int>
#define all(p) p.begin(),p.end()
#define F first
#define S second
using namespace std;
void debug() {cerr << endl;}
template <class T, class ...U> void debug(T a, U ... b) { cerr << a << " "; debug(b...);}
const int INF = 1e13 + 10;
const int MOD = (int) 998244353;
const int N = 2e5 + 9;
int n,m;
vi e[N];
int in[N];
vi ord;
bool tag[N],vis[N];
void dfs(int u){
debug(u);
vis[u] = 1,tag[u] = 1;
for(int c : e[u]){
if(tag[c]){
cout << "-1\n";
exit(0);
}
if(!vis[c]){
dfs(c);
}
}
tag[u] = 0;
ord.pb(u);
}
bool st[N];
void solve(){
//pancake ( ^-^)_
cin >> n >> m;
forn(i,m){
int s,t;
cin >> s >> t;
e[s].pb(t);
in[t]++;
}
Forn(i,n){
if(!vis[i] && in[i] == 0) dfs(i),st[i] = 1;
}
if(ord.size() != n) {
cout << "-1\n";
return;
}
cout << ord.size() << '\n';
reverse(all(ord));
for(auto &i : ord) {
if(st[i]) cout << i << ' ' << 1 << '\n';
else cout << i << ' ' << 0 << '\n';
}
}
signed main(){
cin.tie(NULL);
cout.tie(NULL);
ios_base::sync_with_stdio(0);
solve();
return 0;
}
Compilation message
naboj.cpp: In function 'void solve()':
naboj.cpp:54:16: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
54 | if(ord.size() != n) {
| ~~~~~~~~~~~^~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
3 ms |
5032 KB |
Output is correct |
3 |
Correct |
3 ms |
5032 KB |
Output is correct |
4 |
Correct |
3 ms |
5024 KB |
Output is correct |
5 |
Correct |
3 ms |
4948 KB |
Output is correct |
6 |
Correct |
3 ms |
4948 KB |
Output is correct |
7 |
Correct |
3 ms |
4948 KB |
Output is correct |
8 |
Correct |
3 ms |
5032 KB |
Output is correct |
9 |
Correct |
3 ms |
5036 KB |
Output is correct |
10 |
Correct |
3 ms |
4948 KB |
Output is correct |
11 |
Correct |
3 ms |
5076 KB |
Output is correct |
12 |
Correct |
3 ms |
5028 KB |
Output is correct |
13 |
Correct |
3 ms |
4924 KB |
Output is correct |
14 |
Correct |
3 ms |
4948 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
778 ms |
18852 KB |
Output is correct |
2 |
Correct |
787 ms |
18932 KB |
Output is correct |
3 |
Correct |
410 ms |
12264 KB |
Output is correct |
4 |
Correct |
783 ms |
19124 KB |
Output is correct |
5 |
Correct |
769 ms |
18964 KB |
Output is correct |
6 |
Correct |
773 ms |
19004 KB |
Output is correct |
7 |
Correct |
782 ms |
18992 KB |
Output is correct |
8 |
Correct |
603 ms |
15812 KB |
Output is correct |
9 |
Correct |
789 ms |
18940 KB |
Output is correct |
10 |
Correct |
762 ms |
18924 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
3 ms |
5032 KB |
Output is correct |
3 |
Correct |
3 ms |
5032 KB |
Output is correct |
4 |
Correct |
3 ms |
5024 KB |
Output is correct |
5 |
Correct |
3 ms |
4948 KB |
Output is correct |
6 |
Correct |
3 ms |
4948 KB |
Output is correct |
7 |
Correct |
3 ms |
4948 KB |
Output is correct |
8 |
Correct |
3 ms |
5032 KB |
Output is correct |
9 |
Correct |
3 ms |
5036 KB |
Output is correct |
10 |
Correct |
3 ms |
4948 KB |
Output is correct |
11 |
Correct |
3 ms |
5076 KB |
Output is correct |
12 |
Correct |
3 ms |
5028 KB |
Output is correct |
13 |
Correct |
3 ms |
4924 KB |
Output is correct |
14 |
Correct |
3 ms |
4948 KB |
Output is correct |
15 |
Correct |
778 ms |
18852 KB |
Output is correct |
16 |
Correct |
787 ms |
18932 KB |
Output is correct |
17 |
Correct |
410 ms |
12264 KB |
Output is correct |
18 |
Correct |
783 ms |
19124 KB |
Output is correct |
19 |
Correct |
769 ms |
18964 KB |
Output is correct |
20 |
Correct |
773 ms |
19004 KB |
Output is correct |
21 |
Correct |
782 ms |
18992 KB |
Output is correct |
22 |
Correct |
603 ms |
15812 KB |
Output is correct |
23 |
Correct |
789 ms |
18940 KB |
Output is correct |
24 |
Correct |
762 ms |
18924 KB |
Output is correct |
25 |
Correct |
139 ms |
15768 KB |
Output is correct |
26 |
Correct |
117 ms |
15168 KB |
Output is correct |
27 |
Correct |
138 ms |
16228 KB |
Output is correct |
28 |
Correct |
174 ms |
17656 KB |
Output is correct |
29 |
Correct |
90 ms |
14576 KB |
Output is correct |
30 |
Correct |
174 ms |
17440 KB |
Output is correct |
31 |
Correct |
21 ms |
7340 KB |
Output is correct |
32 |
Correct |
791 ms |
18640 KB |
Output is correct |
33 |
Correct |
879 ms |
21648 KB |
Output is correct |
34 |
Correct |
798 ms |
18868 KB |
Output is correct |
35 |
Correct |
881 ms |
21564 KB |
Output is correct |
36 |
Correct |
774 ms |
18040 KB |
Output is correct |
37 |
Correct |
853 ms |
20644 KB |
Output is correct |
38 |
Correct |
841 ms |
19716 KB |
Output is correct |
39 |
Correct |
890 ms |
21248 KB |
Output is correct |
40 |
Correct |
875 ms |
20468 KB |
Output is correct |
41 |
Correct |
864 ms |
20300 KB |
Output is correct |
42 |
Correct |
908 ms |
21560 KB |
Output is correct |
43 |
Correct |
800 ms |
18748 KB |
Output is correct |
44 |
Correct |
910 ms |
21780 KB |
Output is correct |
45 |
Correct |
822 ms |
18396 KB |
Output is correct |
46 |
Correct |
880 ms |
20388 KB |
Output is correct |