oj.uz

Submission #122121

# Submission time Handle Problem Language Result Execution time Memory
122121 2019-06-27T15:11:03 Z Gustav Network (BOI15_net) C++14
0 / 100
 2 ms 384 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pi;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<pi> vpi;
typedef vector<vi> vvi;
const int inf = 0x3f3f3f3f;
const ll linf = 123456789012345678;
const ll mod = 998244353;
#pragma GCC optimize("Ofast")
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " = " << x << endl

int n;
vvi conn;

int main(){
    cin.sync_with_stdio(false);
    cin.tie(0);
    
    cin >> n;
    conn = vvi(n);
    for(int i = 0; i < n-1; i++){
        int u, v;
        cin >> u >> v;
        u--, v--;
        conn[u].push_back(v);
        conn[v].push_back(u);
    }

    vi u;
    for(int i = 0; i < n; i++) if(conn[i].size() == 1) u.push_back(i);
    cout << (u.size()+1)/2 << "\n";
    for(int i = 1; i < u.size(); i+=2) cout << u[i]+1 << " " << u[i-1]+1 << "\n";
    if(u.size()%2 == 1){
        int to = 0;
        if(u[u.size()-1] == to) to++;
        if(conn[u[u.size()-1]][0] == to) to++;
        if(u[u.size()-1] == to) to++;
        cout << u[u.size()-1]+1 << " " << to+1 << "\n";
    }
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:37:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 1; i < u.size(); i+=2) cout << u[i]+1 << " " << u[i-1]+1 << "\n";
                    ~~^~~~~~~~~~

Subtask #1
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 2 ms 256 KB Output is correct
4 Correct 2 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 2 ms 384 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 2 ms 384 KB Output is correct
9 Correct 2 ms 384 KB Output is correct
10 Incorrect 0 ms 384 KB Breaking single line is causing network to disconnect.
11 Halted 0 ms 0 KB -

Subtask #2
0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 2 ms 256 KB Output is correct
4 Correct 2 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 2 ms 384 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 2 ms 384 KB Output is correct
9 Correct 2 ms 384 KB Output is correct
10 Incorrect 0 ms 384 KB Breaking single line is causing network to disconnect.
11 Halted 0 ms 0 KB -

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 2 ms 256 KB Output is correct
4 Correct 2 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 2 ms 384 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 2 ms 384 KB Output is correct
9 Correct 2 ms 384 KB Output is correct
10 Incorrect 0 ms 384 KB Breaking single line is causing network to disconnect.
11 Halted 0 ms 0 KB -