#include<iostream>
#include<vector>
using namespace std;
int sw()
{
int ret=0,wcz=getchar_unlocked();
while(wcz<'0'||wcz>'9')
wcz=getchar_unlocked();
while(wcz>='0'&&wcz<='9')
{
ret=ret*10+wcz-'0';
wcz=getchar_unlocked();
}
return ret;
}
int n,m;
vector<int>*pol;
bool *juzodw,*terodw;
int *stp_wch,*odp,iter;
bool dfs(int ter)
{
juzodw[ter]=1;
terodw[ter]=1;
for(auto i:pol[ter])
{
if(terodw[i]==1)
return 1;
if(juzodw[i]==0)
if(dfs(i))
return 1;
}
terodw[ter]=0;
odp[++iter]=ter;
return 0;
}
int main()
{
n=sw();m=sw();
pol=new vector<int>[n+1];
juzodw=new bool[n+1];
terodw=new bool[n+1];
odp=new int[n+1];
stp_wch=new int[n+1];
while(m)
{
--m;
int a,b;
a=sw();b=sw();
pol[b].push_back(a);
stp_wch[a]++;
}
for(int i=1;i<=n;++i)
if(stp_wch[i]==0)
if(dfs(i))
{
printf("-1");
return 0;
}
if(iter!=n)
{
printf("-1");
return 0;
}
printf("%d\n",n);
for(int i=1;i<=n;++i)
printf("%d 0\n",odp[i]);
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
0 ms |
212 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
0 ms |
212 KB |
Output is correct |
12 |
Correct |
0 ms |
212 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
14 |
Correct |
0 ms |
212 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
68 ms |
12844 KB |
Output is correct |
2 |
Correct |
93 ms |
12864 KB |
Output is correct |
3 |
Correct |
25 ms |
6880 KB |
Output is correct |
4 |
Correct |
73 ms |
12832 KB |
Output is correct |
5 |
Correct |
82 ms |
12724 KB |
Output is correct |
6 |
Correct |
71 ms |
12832 KB |
Output is correct |
7 |
Correct |
69 ms |
12792 KB |
Output is correct |
8 |
Correct |
48 ms |
10028 KB |
Output is correct |
9 |
Correct |
69 ms |
12788 KB |
Output is correct |
10 |
Correct |
100 ms |
12740 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
0 ms |
212 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
0 ms |
212 KB |
Output is correct |
12 |
Correct |
0 ms |
212 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
14 |
Correct |
0 ms |
212 KB |
Output is correct |
15 |
Correct |
68 ms |
12844 KB |
Output is correct |
16 |
Correct |
93 ms |
12864 KB |
Output is correct |
17 |
Correct |
25 ms |
6880 KB |
Output is correct |
18 |
Correct |
73 ms |
12832 KB |
Output is correct |
19 |
Correct |
82 ms |
12724 KB |
Output is correct |
20 |
Correct |
71 ms |
12832 KB |
Output is correct |
21 |
Correct |
69 ms |
12792 KB |
Output is correct |
22 |
Correct |
48 ms |
10028 KB |
Output is correct |
23 |
Correct |
69 ms |
12788 KB |
Output is correct |
24 |
Correct |
100 ms |
12740 KB |
Output is correct |
25 |
Correct |
60 ms |
8732 KB |
Output is correct |
26 |
Correct |
59 ms |
11204 KB |
Output is correct |
27 |
Correct |
78 ms |
11704 KB |
Output is correct |
28 |
Correct |
124 ms |
12104 KB |
Output is correct |
29 |
Correct |
49 ms |
10828 KB |
Output is correct |
30 |
Correct |
77 ms |
12152 KB |
Output is correct |
31 |
Correct |
9 ms |
1720 KB |
Output is correct |
32 |
Correct |
86 ms |
14860 KB |
Output is correct |
33 |
Correct |
134 ms |
15052 KB |
Output is correct |
34 |
Correct |
90 ms |
14900 KB |
Output is correct |
35 |
Correct |
136 ms |
15096 KB |
Output is correct |
36 |
Correct |
73 ms |
14796 KB |
Output is correct |
37 |
Correct |
119 ms |
14932 KB |
Output is correct |
38 |
Correct |
112 ms |
14840 KB |
Output is correct |
39 |
Correct |
135 ms |
15040 KB |
Output is correct |
40 |
Correct |
121 ms |
14992 KB |
Output is correct |
41 |
Correct |
119 ms |
14952 KB |
Output is correct |
42 |
Correct |
152 ms |
15128 KB |
Output is correct |
43 |
Correct |
94 ms |
14900 KB |
Output is correct |
44 |
Correct |
143 ms |
15112 KB |
Output is correct |
45 |
Correct |
86 ms |
14872 KB |
Output is correct |
46 |
Correct |
143 ms |
14896 KB |
Output is correct |