oj.uz

Submission #270499

# Submission time Handle Problem Language Result Execution time Memory
270499 2020-08-17T16:43:46 Z Hehehe Network (BOI15_net) C++14
0 / 100
 39 ms 47360 KB 
#include<bits/stdc++.h> //:3
using namespace std;
typedef long long ll;
#define all(a) (a).begin(), (a).end()
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define pi pair<int, int>
#define sz(x) (int)((x).size())
//#define int long long

const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};

const ll inf = 2e9;
const ll mod = 1e9 + 7;
const int N = 2e6 + 11;
const ll INF64 = 3e18 + 1;
const double eps = 1e-14;
const double PI = acos(-1);

//ifstream in(".in");
//ofstream out(".out");

int n, m;
vector<int>v[N];

void solve(){

    cin >> n;

    for(int i = 1, x, y; i < n; i++){
        cin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    int root = 0;
    vector<int>leaves;
    for(int i = 1; i <= n; i++){
        if(sz(v[i]) == 1){
            leaves.push_back(i);
        }
        if(sz(v[i]) > 1)root = i;
    }

    cout << sz(leaves)/2 + sz(leaves) % 2 << '\n';

    //cout << "L" <<'\n';
    //for(auto it : leaves)cout << it << ' '; cout << '\n';
    //cout << "R = " << root << '\n';

    for(int i = 0; i < sz(leaves) - 1; i += 2){
        cout << leaves[i] << ' ' << leaves[i + 1] << '\n';
    }

    if(sz(leaves) % 2){
        cout << leaves[sz(leaves) - 1] << ' ' << 1 << '\n';
    }
}

int32_t main(){
    ios_base :: sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int T = 1;
    //cin >> T;
    while(T--){
        solve();
    }
}

Compilation message

net.cpp: In function 'void solve()':
net.cpp:39:9: warning: variable 'root' set but not used [-Wunused-but-set-variable]
   39 |     int root = 0;
      |         ^~~~

Subtask #1
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 38 ms 47224 KB Output is correct
2 Correct 31 ms 47232 KB Output is correct
3 Correct 39 ms 47224 KB Output is correct
4 Correct 32 ms 47232 KB Output is correct
5 Correct 32 ms 47232 KB Output is correct
6 Correct 31 ms 47360 KB Output is correct
7 Correct 32 ms 47224 KB Output is correct
8 Correct 32 ms 47232 KB Output is correct
9 Correct 32 ms 47224 KB Output is correct
10 Incorrect 37 ms 47232 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 38 ms 47224 KB Output is correct
2 Correct 31 ms 47232 KB Output is correct
3 Correct 39 ms 47224 KB Output is correct
4 Correct 32 ms 47232 KB Output is correct
5 Correct 32 ms 47232 KB Output is correct
6 Correct 31 ms 47360 KB Output is correct
7 Correct 32 ms 47224 KB Output is correct
8 Correct 32 ms 47232 KB Output is correct
9 Correct 32 ms 47224 KB Output is correct
10 Incorrect 37 ms 47232 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 38 ms 47224 KB Output is correct
2 Correct 31 ms 47232 KB Output is correct
3 Correct 39 ms 47224 KB Output is correct
4 Correct 32 ms 47232 KB Output is correct
5 Correct 32 ms 47232 KB Output is correct
6 Correct 31 ms 47360 KB Output is correct
7 Correct 32 ms 47224 KB Output is correct
8 Correct 32 ms 47232 KB Output is correct
9 Correct 32 ms 47224 KB Output is correct
10 Incorrect 37 ms 47232 KB Breaking single line is causing network to disconnect.
11 Halted 0 ms 0 KB -