oj.uz

Submission #32310

# Submission time Handle Problem Language Result Execution time Memory
32310 2017-10-08T12:33:42 Z dqhungdl Network (BOI15_net) C++14
0 / 100
 3 ms 14224 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()
{
    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;
        }
    int i=0,j=V.size()-1;
    while(i<j)
    {
        rs.push_back(ii(V[i],V[j]));
        i++;
        j--;
    }
    if(i==j)
        rs.push_back(ii(V[i],V[0]));
    cout<<rs.size()<<"\n";
    for(int i=0;i<rs.size();i++)
        cout<<rs[i].first<<' '<<rs[i].second<<"\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:49:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<rs.size();i++)
                  ^

Subtask #1
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14224 KB Output is correct
2 Incorrect 3 ms 14224 KB Breaking single line is causing network to disconnect.
3 Halted 0 ms 0 KB -

Subtask #2
0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14224 KB Output is correct
2 Incorrect 3 ms 14224 KB Breaking single line is causing network to disconnect.
3 Halted 0 ms 0 KB -

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14224 KB Output is correct
2 Incorrect 3 ms 14224 KB Breaking single line is causing network to disconnect.
3 Halted 0 ms 0 KB -