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Submission #96091

# Submission time Handle Problem Language Result Execution time Memory
96091 2019-02-05T17:56:23 Z andrei110901 Network (BOI15_net) C++14
63 / 100
 2000 ms 38692 KB 
#include <bits/stdc++.h>

using namespace std;

vector <vector <int>> ad, gramezi;
vector <int> sub;
int nrf, cf;

void dfs(int nod, int par){
    if(ad[nod].size() == 1)
        sub[nod] = 1;
    for(auto fiu : ad[nod])
        if(fiu != par){
            dfs(fiu, nod);
            sub[nod] += sub[fiu];
        }
}

int get_centroid(int nod, int par){
    for(auto fiu : ad[nod])
        if(fiu != par && sub[fiu] > nrf / 2)
            return get_centroid(fiu, nod);
    return nod;
}


bool cmp(const int &lhs, const int &rhs){
    return gramezi[lhs].size() > gramezi[rhs].size();
}


void Frunza(int nod, int par, vector <int> &v){
    if(ad[nod].size() == 1){
        v.push_back(nod);
        return;
    }
    for(auto fiu : ad[nod])
        if(fiu != par)
            Frunza(fiu, nod, v);
}

int main()
{
    int n, x, y;
    ios::sync_with_stdio(false);
    cin >> n;
    nrf = n;
    ad.resize(n + 1);
    sub.resize(n + 1);
    for(int i = 1; i < n; i++){
        cin >> x >> y;
        ad[x].push_back(y);
        ad[y].push_back(x);
    }
    dfs(1, 0);
    nrf = sub[1];
    cf = get_centroid(1, 0);
    vector <int> pa;
    for(auto fiu : ad[cf]){
        vector <int> v;
        pa.push_back(gramezi.size());
        gramezi.push_back(v);
        Frunza(fiu, cf, gramezi.back());
    }
    sort(pa.begin(), pa.end(), cmp);
    cout << (nrf + 1) / 2 << '\n';
    if(nrf % 2 == 1){
        cout << cf << ' ' << gramezi[pa[0]].back() << '\n';
        gramezi[pa[0]].pop_back();
        sort(pa.begin(), pa.end(), cmp);
    }
    while(gramezi[pa[0]].size() > 0){
        cout << gramezi[pa[0]].back() << ' ' << gramezi[pa[1]].back() << '\n';
        gramezi[pa[0]].pop_back();
        gramezi[pa[1]].pop_back();
        sort(pa.begin(), pa.end(), cmp);
    }
    return 0;
}

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 256 KB Output is correct
5 Correct 2 ms 380 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 2 ms 376 KB Output is correct
13 Correct 2 ms 256 KB Output is correct
14 Correct 2 ms 376 KB Output is correct
15 Correct 2 ms 376 KB Output is correct
16 Correct 2 ms 256 KB Output is correct
17 Correct 2 ms 256 KB Output is correct
18 Correct 2 ms 376 KB Output is correct
19 Correct 2 ms 380 KB Output is correct
20 Correct 2 ms 376 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 256 KB Output is correct
5 Correct 2 ms 380 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 2 ms 376 KB Output is correct
13 Correct 2 ms 256 KB Output is correct
14 Correct 2 ms 376 KB Output is correct
15 Correct 2 ms 376 KB Output is correct
16 Correct 2 ms 256 KB Output is correct
17 Correct 2 ms 256 KB Output is correct
18 Correct 2 ms 376 KB Output is correct
19 Correct 2 ms 380 KB Output is correct
20 Correct 2 ms 376 KB Output is correct
21 Correct 2 ms 376 KB Output is correct
22 Correct 27 ms 496 KB Output is correct
23 Correct 26 ms 508 KB Output is correct
24 Correct 64 ms 668 KB Output is correct
25 Correct 12 ms 504 KB Output is correct
26 Correct 8 ms 504 KB Output is correct
27 Correct 2 ms 504 KB Output is correct
28 Correct 2 ms 504 KB Output is correct
29 Correct 3 ms 504 KB Output is correct
30 Correct 2 ms 376 KB Output is correct
31 Correct 3 ms 528 KB Output is correct
32 Correct 2 ms 252 KB Output is correct
33 Correct 2 ms 256 KB Output is correct
34 Correct 2 ms 376 KB Output is correct
35 Correct 2 ms 296 KB Output is correct
36 Correct 2 ms 376 KB Output is correct
37 Correct 2 ms 376 KB Output is correct
38 Correct 2 ms 504 KB Output is correct
39 Correct 2 ms 376 KB Output is correct
40 Correct 2 ms 376 KB Output is correct
41 Correct 2 ms 376 KB Output is correct
42 Correct 5 ms 376 KB Output is correct
43 Correct 16 ms 504 KB Output is correct
44 Correct 2 ms 380 KB Output is correct
45 Correct 2 ms 376 KB Output is correct
46 Correct 2 ms 376 KB Output is correct
47 Correct 2 ms 376 KB Output is correct
48 Correct 2 ms 376 KB Output is correct
49 Correct 7 ms 376 KB Output is correct
50 Correct 2 ms 376 KB Output is correct
51 Correct 2 ms 376 KB Output is correct
52 Correct 2 ms 376 KB Output is correct
53 Correct 2 ms 376 KB Output is correct
54 Correct 2 ms 376 KB Output is correct
55 Correct 2 ms 376 KB Output is correct
56 Correct 2 ms 376 KB Output is correct
57 Correct 3 ms 376 KB Output is correct
58 Correct 3 ms 504 KB Output is correct

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 256 KB Output is correct
5 Correct 2 ms 380 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 2 ms 376 KB Output is correct
13 Correct 2 ms 256 KB Output is correct
14 Correct 2 ms 376 KB Output is correct
15 Correct 2 ms 376 KB Output is correct
16 Correct 2 ms 256 KB Output is correct
17 Correct 2 ms 256 KB Output is correct
18 Correct 2 ms 376 KB Output is correct
19 Correct 2 ms 380 KB Output is correct
20 Correct 2 ms 376 KB Output is correct
21 Correct 2 ms 376 KB Output is correct
22 Correct 27 ms 496 KB Output is correct
23 Correct 26 ms 508 KB Output is correct
24 Correct 64 ms 668 KB Output is correct
25 Correct 12 ms 504 KB Output is correct
26 Correct 8 ms 504 KB Output is correct
27 Correct 2 ms 504 KB Output is correct
28 Correct 2 ms 504 KB Output is correct
29 Correct 3 ms 504 KB Output is correct
30 Correct 2 ms 376 KB Output is correct
31 Correct 3 ms 528 KB Output is correct
32 Correct 2 ms 252 KB Output is correct
33 Correct 2 ms 256 KB Output is correct
34 Correct 2 ms 376 KB Output is correct
35 Correct 2 ms 296 KB Output is correct
36 Correct 2 ms 376 KB Output is correct
37 Correct 2 ms 376 KB Output is correct
38 Correct 2 ms 504 KB Output is correct
39 Correct 2 ms 376 KB Output is correct
40 Correct 2 ms 376 KB Output is correct
41 Correct 2 ms 376 KB Output is correct
42 Correct 5 ms 376 KB Output is correct
43 Correct 16 ms 504 KB Output is correct
44 Correct 2 ms 380 KB Output is correct
45 Correct 2 ms 376 KB Output is correct
46 Correct 2 ms 376 KB Output is correct
47 Correct 2 ms 376 KB Output is correct
48 Correct 2 ms 376 KB Output is correct
49 Correct 7 ms 376 KB Output is correct
50 Correct 2 ms 376 KB Output is correct
51 Correct 2 ms 376 KB Output is correct
52 Correct 2 ms 376 KB Output is correct
53 Correct 2 ms 376 KB Output is correct
54 Correct 2 ms 376 KB Output is correct
55 Correct 2 ms 376 KB Output is correct
56 Correct 2 ms 376 KB Output is correct
57 Correct 3 ms 376 KB Output is correct
58 Correct 3 ms 504 KB Output is correct
59 Execution timed out 2054 ms 38692 KB Time limit exceeded
60 Halted 0 ms 0 KB -