oj.uz

Submission #32311

# Submission time Handle Problem Language Result Execution time Memory
32311 2017-10-08T14:10:28 Z dqhungdl Network (BOI15_net) C++14
18 / 100
 6 ms 14384 KB 
#include <bits/stdc++.h>
using namespace std;

typedef pair<int,int> ii;
int n;
bool Free[500005];
vector<int> V,g[500005];
vector<ii> rs;

void DFS(int u)
{
    Free[u]=true;
    if(g[u].size()==1)
    {
        V.push_back(u);
        return;
    }
    for(int i=0;i<g[u].size();i++)
        if(Free[g[u][i]]==false)
            DFS(g[u][i]);
}

int main()
{
    ios_base::sync_with_stdio(false);
    //freopen("NET.INP","r",stdin);
    cin>>n;
    int u,v;
    for(int i=1;i<n;i++)
    {
        cin>>u>>v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    for(int i=1;i<=n;i++)
        if(g[i].size()>=2)
        {
            DFS(i);
            break;
        }
    cout<<(V.size()+1)/2<<"\n";
    for(int i=0;i<=(V.size()-1)/2;i++)
        cout<<V[i]<<' '<<V[i+V.size()/2]<<"\n";
}

Compilation message

net.cpp: In function 'void DFS(int)':
net.cpp:18:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<g[u].size();i++)
                  ^
net.cpp: In function 'int main()':
net.cpp:42:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<=(V.size()-1)/2;i++)
                  ^

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14384 KB Output is correct
2 Correct 3 ms 14384 KB Output is correct
3 Correct 0 ms 14384 KB Output is correct
4 Correct 0 ms 14384 KB Output is correct
5 Correct 3 ms 14384 KB Output is correct
6 Correct 0 ms 14384 KB Output is correct
7 Correct 3 ms 14384 KB Output is correct
8 Correct 0 ms 14384 KB Output is correct
9 Correct 0 ms 14384 KB Output is correct
10 Correct 6 ms 14384 KB Output is correct
11 Correct 0 ms 14384 KB Output is correct
12 Correct 0 ms 14384 KB Output is correct
13 Correct 0 ms 14384 KB Output is correct
14 Correct 3 ms 14384 KB Output is correct
15 Correct 0 ms 14384 KB Output is correct
16 Correct 3 ms 14384 KB Output is correct
17 Correct 0 ms 14384 KB Output is correct
18 Correct 0 ms 14384 KB Output is correct
19 Correct 3 ms 14384 KB Output is correct
20 Correct 0 ms 14384 KB Output is correct

Subtask #2
0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14384 KB Output is correct
2 Correct 3 ms 14384 KB Output is correct
3 Correct 0 ms 14384 KB Output is correct
4 Correct 0 ms 14384 KB Output is correct
5 Correct 3 ms 14384 KB Output is correct
6 Correct 0 ms 14384 KB Output is correct
7 Correct 3 ms 14384 KB Output is correct
8 Correct 0 ms 14384 KB Output is correct
9 Correct 0 ms 14384 KB Output is correct
10 Correct 6 ms 14384 KB Output is correct
11 Correct 0 ms 14384 KB Output is correct
12 Correct 0 ms 14384 KB Output is correct
13 Correct 0 ms 14384 KB Output is correct
14 Correct 3 ms 14384 KB Output is correct
15 Correct 0 ms 14384 KB Output is correct
16 Correct 3 ms 14384 KB Output is correct
17 Correct 0 ms 14384 KB Output is correct
18 Correct 0 ms 14384 KB Output is correct
19 Correct 3 ms 14384 KB Output is correct
20 Correct 0 ms 14384 KB Output is correct
21 Correct 3 ms 14384 KB Output is correct
22 Runtime error 3 ms 14384 KB Execution killed because of forbidden syscall writev (20)
23 Halted 0 ms 0 KB -

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14384 KB Output is correct
2 Correct 3 ms 14384 KB Output is correct
3 Correct 0 ms 14384 KB Output is correct
4 Correct 0 ms 14384 KB Output is correct
5 Correct 3 ms 14384 KB Output is correct
6 Correct 0 ms 14384 KB Output is correct
7 Correct 3 ms 14384 KB Output is correct
8 Correct 0 ms 14384 KB Output is correct
9 Correct 0 ms 14384 KB Output is correct
10 Correct 6 ms 14384 KB Output is correct
11 Correct 0 ms 14384 KB Output is correct
12 Correct 0 ms 14384 KB Output is correct
13 Correct 0 ms 14384 KB Output is correct
14 Correct 3 ms 14384 KB Output is correct
15 Correct 0 ms 14384 KB Output is correct
16 Correct 3 ms 14384 KB Output is correct
17 Correct 0 ms 14384 KB Output is correct
18 Correct 0 ms 14384 KB Output is correct
19 Correct 3 ms 14384 KB Output is correct
20 Correct 0 ms 14384 KB Output is correct
21 Correct 3 ms 14384 KB Output is correct
22 Runtime error 3 ms 14384 KB Execution killed because of forbidden syscall writev (20)
23 Halted 0 ms 0 KB -