#include <bits/stdc++.h>
//#pragma GCC optimize("Ofast")
#define LL long long
#define se second
#define fi first
using namespace std;
const int N = 2e5 + 7;
const int mod = 1e9 + 7;
const int B = sqrt(N);
int n;
bool used[N];
vector < int > v[N];
vector < int > ans;
void dfs( int x , int p )
{
if( v[x].size() == 1 && !used[x] ){
ans.push_back(x);
}
used[x] = true;
for( auto y : v[x] ){
if( y == p )continue;
dfs(y , x);
}
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(NULL);
//freopen( "input.txt" , "r" , stdin );
//freopen( "output.txt" , "w" , stdout );
cin >> n;
for( int i = 1; i < n; i++ ){
int x,y;
cin >> x >> y;
v[x].push_back(y);
v[y].push_back(x);
}
int x = 1;
for( int i = 1; i <= n; i++ ){
if( v[i].size() > 1 ){
x = i;
}
}
dfs(x , x);
int k = (ans.size() + 1) / 2;
cout << ( (int)ans.size() + 1 ) / 2 << "\n";
for( int i = 0; i < ( ans.size() + 1) / 2; i++ ){
cout << ans[i] << " " << ans[ (i + k) % (int)ans.size() ] << "\n";
}
}
Compilation message
net.cpp: In function 'int main()':
net.cpp:54:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for( int i = 0; i < ( ans.size() + 1) / 2; i++ ){
~~^~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
4988 KB |
Output is correct |
2 |
Correct |
6 ms |
4984 KB |
Output is correct |
3 |
Correct |
6 ms |
5112 KB |
Output is correct |
4 |
Correct |
6 ms |
4984 KB |
Output is correct |
5 |
Correct |
7 ms |
4984 KB |
Output is correct |
6 |
Correct |
7 ms |
4984 KB |
Output is correct |
7 |
Correct |
6 ms |
5048 KB |
Output is correct |
8 |
Correct |
7 ms |
5112 KB |
Output is correct |
9 |
Correct |
8 ms |
4984 KB |
Output is correct |
10 |
Correct |
8 ms |
5112 KB |
Output is correct |
11 |
Correct |
6 ms |
5112 KB |
Output is correct |
12 |
Correct |
6 ms |
4984 KB |
Output is correct |
13 |
Correct |
7 ms |
5112 KB |
Output is correct |
14 |
Correct |
7 ms |
5112 KB |
Output is correct |
15 |
Correct |
7 ms |
4984 KB |
Output is correct |
16 |
Correct |
9 ms |
5112 KB |
Output is correct |
17 |
Correct |
8 ms |
5112 KB |
Output is correct |
18 |
Correct |
5 ms |
4984 KB |
Output is correct |
19 |
Correct |
7 ms |
4984 KB |
Output is correct |
20 |
Correct |
6 ms |
4984 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
4988 KB |
Output is correct |
2 |
Correct |
6 ms |
4984 KB |
Output is correct |
3 |
Correct |
6 ms |
5112 KB |
Output is correct |
4 |
Correct |
6 ms |
4984 KB |
Output is correct |
5 |
Correct |
7 ms |
4984 KB |
Output is correct |
6 |
Correct |
7 ms |
4984 KB |
Output is correct |
7 |
Correct |
6 ms |
5048 KB |
Output is correct |
8 |
Correct |
7 ms |
5112 KB |
Output is correct |
9 |
Correct |
8 ms |
4984 KB |
Output is correct |
10 |
Correct |
8 ms |
5112 KB |
Output is correct |
11 |
Correct |
6 ms |
5112 KB |
Output is correct |
12 |
Correct |
6 ms |
4984 KB |
Output is correct |
13 |
Correct |
7 ms |
5112 KB |
Output is correct |
14 |
Correct |
7 ms |
5112 KB |
Output is correct |
15 |
Correct |
7 ms |
4984 KB |
Output is correct |
16 |
Correct |
9 ms |
5112 KB |
Output is correct |
17 |
Correct |
8 ms |
5112 KB |
Output is correct |
18 |
Correct |
5 ms |
4984 KB |
Output is correct |
19 |
Correct |
7 ms |
4984 KB |
Output is correct |
20 |
Correct |
6 ms |
4984 KB |
Output is correct |
21 |
Correct |
6 ms |
4984 KB |
Output is correct |
22 |
Correct |
7 ms |
5112 KB |
Output is correct |
23 |
Correct |
7 ms |
5240 KB |
Output is correct |
24 |
Correct |
8 ms |
5240 KB |
Output is correct |
25 |
Correct |
8 ms |
5112 KB |
Output is correct |
26 |
Correct |
7 ms |
5112 KB |
Output is correct |
27 |
Correct |
7 ms |
5112 KB |
Output is correct |
28 |
Correct |
8 ms |
5112 KB |
Output is correct |
29 |
Correct |
7 ms |
5112 KB |
Output is correct |
30 |
Correct |
7 ms |
5112 KB |
Output is correct |
31 |
Correct |
10 ms |
5112 KB |
Output is correct |
32 |
Correct |
6 ms |
4984 KB |
Output is correct |
33 |
Correct |
6 ms |
4988 KB |
Output is correct |
34 |
Correct |
6 ms |
4984 KB |
Output is correct |
35 |
Correct |
6 ms |
5112 KB |
Output is correct |
36 |
Correct |
6 ms |
4984 KB |
Output is correct |
37 |
Correct |
7 ms |
5112 KB |
Output is correct |
38 |
Correct |
8 ms |
5112 KB |
Output is correct |
39 |
Correct |
8 ms |
5084 KB |
Output is correct |
40 |
Correct |
8 ms |
5112 KB |
Output is correct |
41 |
Correct |
8 ms |
5112 KB |
Output is correct |
42 |
Correct |
7 ms |
5112 KB |
Output is correct |
43 |
Correct |
8 ms |
5108 KB |
Output is correct |
44 |
Correct |
6 ms |
4984 KB |
Output is correct |
45 |
Correct |
6 ms |
4984 KB |
Output is correct |
46 |
Correct |
7 ms |
5112 KB |
Output is correct |
47 |
Correct |
7 ms |
5112 KB |
Output is correct |
48 |
Correct |
6 ms |
4984 KB |
Output is correct |
49 |
Correct |
7 ms |
5112 KB |
Output is correct |
50 |
Correct |
6 ms |
5112 KB |
Output is correct |
51 |
Correct |
6 ms |
5112 KB |
Output is correct |
52 |
Correct |
6 ms |
4984 KB |
Output is correct |
53 |
Correct |
7 ms |
5116 KB |
Output is correct |
54 |
Correct |
7 ms |
5240 KB |
Output is correct |
55 |
Correct |
6 ms |
4984 KB |
Output is correct |
56 |
Correct |
6 ms |
4984 KB |
Output is correct |
57 |
Correct |
8 ms |
4984 KB |
Output is correct |
58 |
Correct |
7 ms |
4984 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
4988 KB |
Output is correct |
2 |
Correct |
6 ms |
4984 KB |
Output is correct |
3 |
Correct |
6 ms |
5112 KB |
Output is correct |
4 |
Correct |
6 ms |
4984 KB |
Output is correct |
5 |
Correct |
7 ms |
4984 KB |
Output is correct |
6 |
Correct |
7 ms |
4984 KB |
Output is correct |
7 |
Correct |
6 ms |
5048 KB |
Output is correct |
8 |
Correct |
7 ms |
5112 KB |
Output is correct |
9 |
Correct |
8 ms |
4984 KB |
Output is correct |
10 |
Correct |
8 ms |
5112 KB |
Output is correct |
11 |
Correct |
6 ms |
5112 KB |
Output is correct |
12 |
Correct |
6 ms |
4984 KB |
Output is correct |
13 |
Correct |
7 ms |
5112 KB |
Output is correct |
14 |
Correct |
7 ms |
5112 KB |
Output is correct |
15 |
Correct |
7 ms |
4984 KB |
Output is correct |
16 |
Correct |
9 ms |
5112 KB |
Output is correct |
17 |
Correct |
8 ms |
5112 KB |
Output is correct |
18 |
Correct |
5 ms |
4984 KB |
Output is correct |
19 |
Correct |
7 ms |
4984 KB |
Output is correct |
20 |
Correct |
6 ms |
4984 KB |
Output is correct |
21 |
Correct |
6 ms |
4984 KB |
Output is correct |
22 |
Correct |
7 ms |
5112 KB |
Output is correct |
23 |
Correct |
7 ms |
5240 KB |
Output is correct |
24 |
Correct |
8 ms |
5240 KB |
Output is correct |
25 |
Correct |
8 ms |
5112 KB |
Output is correct |
26 |
Correct |
7 ms |
5112 KB |
Output is correct |
27 |
Correct |
7 ms |
5112 KB |
Output is correct |
28 |
Correct |
8 ms |
5112 KB |
Output is correct |
29 |
Correct |
7 ms |
5112 KB |
Output is correct |
30 |
Correct |
7 ms |
5112 KB |
Output is correct |
31 |
Correct |
10 ms |
5112 KB |
Output is correct |
32 |
Correct |
6 ms |
4984 KB |
Output is correct |
33 |
Correct |
6 ms |
4988 KB |
Output is correct |
34 |
Correct |
6 ms |
4984 KB |
Output is correct |
35 |
Correct |
6 ms |
5112 KB |
Output is correct |
36 |
Correct |
6 ms |
4984 KB |
Output is correct |
37 |
Correct |
7 ms |
5112 KB |
Output is correct |
38 |
Correct |
8 ms |
5112 KB |
Output is correct |
39 |
Correct |
8 ms |
5084 KB |
Output is correct |
40 |
Correct |
8 ms |
5112 KB |
Output is correct |
41 |
Correct |
8 ms |
5112 KB |
Output is correct |
42 |
Correct |
7 ms |
5112 KB |
Output is correct |
43 |
Correct |
8 ms |
5108 KB |
Output is correct |
44 |
Correct |
6 ms |
4984 KB |
Output is correct |
45 |
Correct |
6 ms |
4984 KB |
Output is correct |
46 |
Correct |
7 ms |
5112 KB |
Output is correct |
47 |
Correct |
7 ms |
5112 KB |
Output is correct |
48 |
Correct |
6 ms |
4984 KB |
Output is correct |
49 |
Correct |
7 ms |
5112 KB |
Output is correct |
50 |
Correct |
6 ms |
5112 KB |
Output is correct |
51 |
Correct |
6 ms |
5112 KB |
Output is correct |
52 |
Correct |
6 ms |
4984 KB |
Output is correct |
53 |
Correct |
7 ms |
5116 KB |
Output is correct |
54 |
Correct |
7 ms |
5240 KB |
Output is correct |
55 |
Correct |
6 ms |
4984 KB |
Output is correct |
56 |
Correct |
6 ms |
4984 KB |
Output is correct |
57 |
Correct |
8 ms |
4984 KB |
Output is correct |
58 |
Correct |
7 ms |
4984 KB |
Output is correct |
59 |
Runtime error |
13 ms |
9976 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
60 |
Halted |
0 ms |
0 KB |
- |