oj.uz

Submission #394612

# Submission time Handle Problem Language Result Execution time Memory
394612 2021-04-27T05:52:25 Z fammo Network (BOI15_net) C++11
100 / 100
 938 ms 85704 KB 
#include <bits/stdc++.h>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
typedef long double ld;
#define X first
#define Y second
#define pb push_back
#define fastio ios_base::sync_with_stdio(0);cin.tie(nullptr);cout.tie(nullptr);
#define rndom mt19937 rng(chrono::steady_clock::now().time_since_epoch().count())
#define endl '\n'
//#define int ll
const int  N = 500 * 1000 + 20, MOD = 1e9+7,  base =727;
int n, st[N], low[N], tim;
vector<int>adj[N], leaf;
vector<pii>g[N];
bool mark[N];
void dfs(int v, int p){
    if(int(adj[v].size()) == 1)leaf.pb(v);
    for(int u : adj[v])if(u!=p)dfs(u,v);
    return;
}void check(int v, int e){
    st[v] = low[v] = ++tim;
    mark[v] = 1;
    for(auto p : g[v]){
        int u = p.first, i = p.second;
        if(!mark[u]){
            check(u, i);
            low[v] = min(low[u], low[v]);
            if(low[u] > st[v])
                while(1)tim++;
        }
        else if(i != e)
            low[v] = min(low[v], st[u]);
    }
    return;
}
int32_t main(){
    fastio;
    ///auto t = clock();
    cin >> n;
    for(int i = 0; i < n - 1; i ++){
        int u, v;
        cin >> u >> v;
        u --; v --;
        adj[u].pb(v); adj[v].pb(u);
        g[v].pb({u,i}); g[u].pb({v,i});
    }int root = 0;
    for(int i = 0; i < n; i ++){if(int(adj[i].size()) >2){root = i;}}
    if(int(adj[root].size()<=2)){
        cout << 1 << endl;
        for(int i =0 ; i < n; i ++)if((int)adj[i].size() == 1)cout << i +1 << ' ';
        cout << endl;
        return 0;
    }
    dfs(root,-1);
    int k = (int(leaf.size()))/2;
    int ans  = (int(leaf.size()) + 1)/2;
    for(int i = 0; i < ans; i ++){
        int u = leaf[i], v = leaf[i+k];
        g[v].pb({u,i+n-1}); g[u].pb({v,i+n-1});
    }
    check(root,-1);
    cout << ans << endl;
    for(int i = 0; i < ans; i ++){
        cout << leaf[i] + 1 << ' ' << leaf[i+k] + 1 << endl;
    }
    ///cout << clock() - t << "ms" << endl;
    return 0;

}

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 23756 KB Output is correct
2 Correct 15 ms 23808 KB Output is correct
3 Correct 15 ms 23724 KB Output is correct
4 Correct 15 ms 23768 KB Output is correct
5 Correct 15 ms 23788 KB Output is correct
6 Correct 15 ms 23756 KB Output is correct
7 Correct 15 ms 23820 KB Output is correct
8 Correct 15 ms 23756 KB Output is correct
9 Correct 15 ms 23756 KB Output is correct
10 Correct 15 ms 23820 KB Output is correct
11 Correct 15 ms 23740 KB Output is correct
12 Correct 14 ms 23712 KB Output is correct
13 Correct 16 ms 23756 KB Output is correct
14 Correct 15 ms 23700 KB Output is correct
15 Correct 15 ms 23756 KB Output is correct
16 Correct 16 ms 23828 KB Output is correct
17 Correct 16 ms 23884 KB Output is correct
18 Correct 15 ms 23760 KB Output is correct
19 Correct 15 ms 23756 KB Output is correct
20 Correct 15 ms 23728 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 23756 KB Output is correct
2 Correct 15 ms 23808 KB Output is correct
3 Correct 15 ms 23724 KB Output is correct
4 Correct 15 ms 23768 KB Output is correct
5 Correct 15 ms 23788 KB Output is correct
6 Correct 15 ms 23756 KB Output is correct
7 Correct 15 ms 23820 KB Output is correct
8 Correct 15 ms 23756 KB Output is correct
9 Correct 15 ms 23756 KB Output is correct
10 Correct 15 ms 23820 KB Output is correct
11 Correct 15 ms 23740 KB Output is correct
12 Correct 14 ms 23712 KB Output is correct
13 Correct 16 ms 23756 KB Output is correct
14 Correct 15 ms 23700 KB Output is correct
15 Correct 15 ms 23756 KB Output is correct
16 Correct 16 ms 23828 KB Output is correct
17 Correct 16 ms 23884 KB Output is correct
18 Correct 15 ms 23760 KB Output is correct
19 Correct 15 ms 23756 KB Output is correct
20 Correct 15 ms 23728 KB Output is correct
21 Correct 14 ms 23808 KB Output is correct
22 Correct 16 ms 23964 KB Output is correct
23 Correct 16 ms 24012 KB Output is correct
24 Correct 16 ms 23884 KB Output is correct
25 Correct 16 ms 23884 KB Output is correct
26 Correct 16 ms 23844 KB Output is correct
27 Correct 16 ms 24040 KB Output is correct
28 Correct 17 ms 24028 KB Output is correct
29 Correct 16 ms 23884 KB Output is correct
30 Correct 15 ms 23756 KB Output is correct
31 Correct 17 ms 24040 KB Output is correct
32 Correct 15 ms 23760 KB Output is correct
33 Correct 16 ms 23756 KB Output is correct
34 Correct 15 ms 23800 KB Output is correct
35 Correct 15 ms 23772 KB Output is correct
36 Correct 16 ms 23756 KB Output is correct
37 Correct 16 ms 23848 KB Output is correct
38 Correct 18 ms 23884 KB Output is correct
39 Correct 16 ms 23720 KB Output is correct
40 Correct 15 ms 23828 KB Output is correct
41 Correct 16 ms 23732 KB Output is correct
42 Correct 16 ms 23868 KB Output is correct
43 Correct 16 ms 23884 KB Output is correct
44 Correct 15 ms 23820 KB Output is correct
45 Correct 15 ms 23756 KB Output is correct
46 Correct 15 ms 23824 KB Output is correct
47 Correct 15 ms 23704 KB Output is correct
48 Correct 16 ms 23756 KB Output is correct
49 Correct 16 ms 23884 KB Output is correct
50 Correct 15 ms 23756 KB Output is correct
51 Correct 15 ms 23756 KB Output is correct
52 Correct 16 ms 23756 KB Output is correct
53 Correct 16 ms 23884 KB Output is correct
54 Correct 15 ms 23756 KB Output is correct
55 Correct 16 ms 23756 KB Output is correct
56 Correct 16 ms 23756 KB Output is correct
57 Correct 15 ms 23872 KB Output is correct
58 Correct 16 ms 24000 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 23756 KB Output is correct
2 Correct 15 ms 23808 KB Output is correct
3 Correct 15 ms 23724 KB Output is correct
4 Correct 15 ms 23768 KB Output is correct
5 Correct 15 ms 23788 KB Output is correct
6 Correct 15 ms 23756 KB Output is correct
7 Correct 15 ms 23820 KB Output is correct
8 Correct 15 ms 23756 KB Output is correct
9 Correct 15 ms 23756 KB Output is correct
10 Correct 15 ms 23820 KB Output is correct
11 Correct 15 ms 23740 KB Output is correct
12 Correct 14 ms 23712 KB Output is correct
13 Correct 16 ms 23756 KB Output is correct
14 Correct 15 ms 23700 KB Output is correct
15 Correct 15 ms 23756 KB Output is correct
16 Correct 16 ms 23828 KB Output is correct
17 Correct 16 ms 23884 KB Output is correct
18 Correct 15 ms 23760 KB Output is correct
19 Correct 15 ms 23756 KB Output is correct
20 Correct 15 ms 23728 KB Output is correct
21 Correct 14 ms 23808 KB Output is correct
22 Correct 16 ms 23964 KB Output is correct
23 Correct 16 ms 24012 KB Output is correct
24 Correct 16 ms 23884 KB Output is correct
25 Correct 16 ms 23884 KB Output is correct
26 Correct 16 ms 23844 KB Output is correct
27 Correct 16 ms 24040 KB Output is correct
28 Correct 17 ms 24028 KB Output is correct
29 Correct 16 ms 23884 KB Output is correct
30 Correct 15 ms 23756 KB Output is correct
31 Correct 17 ms 24040 KB Output is correct
32 Correct 15 ms 23760 KB Output is correct
33 Correct 16 ms 23756 KB Output is correct
34 Correct 15 ms 23800 KB Output is correct
35 Correct 15 ms 23772 KB Output is correct
36 Correct 16 ms 23756 KB Output is correct
37 Correct 16 ms 23848 KB Output is correct
38 Correct 18 ms 23884 KB Output is correct
39 Correct 16 ms 23720 KB Output is correct
40 Correct 15 ms 23828 KB Output is correct
41 Correct 16 ms 23732 KB Output is correct
42 Correct 16 ms 23868 KB Output is correct
43 Correct 16 ms 23884 KB Output is correct
44 Correct 15 ms 23820 KB Output is correct
45 Correct 15 ms 23756 KB Output is correct
46 Correct 15 ms 23824 KB Output is correct
47 Correct 15 ms 23704 KB Output is correct
48 Correct 16 ms 23756 KB Output is correct
49 Correct 16 ms 23884 KB Output is correct
50 Correct 15 ms 23756 KB Output is correct
51 Correct 15 ms 23756 KB Output is correct
52 Correct 16 ms 23756 KB Output is correct
53 Correct 16 ms 23884 KB Output is correct
54 Correct 15 ms 23756 KB Output is correct
55 Correct 16 ms 23756 KB Output is correct
56 Correct 16 ms 23756 KB Output is correct
57 Correct 15 ms 23872 KB Output is correct
58 Correct 16 ms 24000 KB Output is correct
59 Correct 768 ms 63324 KB Output is correct
60 Correct 937 ms 70812 KB Output is correct
61 Correct 16 ms 23756 KB Output is correct
62 Correct 15 ms 23700 KB Output is correct
63 Correct 665 ms 58448 KB Output is correct
64 Correct 19 ms 24396 KB Output is correct
65 Correct 32 ms 26724 KB Output is correct
66 Correct 273 ms 43288 KB Output is correct
67 Correct 624 ms 55236 KB Output is correct
68 Correct 910 ms 81856 KB Output is correct
69 Correct 25 ms 25164 KB Output is correct
70 Correct 186 ms 39328 KB Output is correct
71 Correct 649 ms 72732 KB Output is correct
72 Correct 684 ms 71904 KB Output is correct
73 Correct 204 ms 36284 KB Output is correct
74 Correct 912 ms 67780 KB Output is correct
75 Correct 56 ms 29060 KB Output is correct
76 Correct 721 ms 70400 KB Output is correct
77 Correct 663 ms 70828 KB Output is correct
78 Correct 64 ms 29468 KB Output is correct
79 Correct 897 ms 85704 KB Output is correct
80 Correct 18 ms 24140 KB Output is correct
81 Correct 232 ms 39344 KB Output is correct
82 Correct 778 ms 68392 KB Output is correct
83 Correct 913 ms 67776 KB Output is correct
84 Correct 906 ms 68112 KB Output is correct
85 Correct 906 ms 67768 KB Output is correct
86 Correct 920 ms 69608 KB Output is correct
87 Correct 938 ms 70140 KB Output is correct