Submission #710578

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
710578	2023-03-15T11:39:20 Z	PoonYaPat	Network (BOI15_net)	C++14	100 / 100	477 ms	52128 KB

#include <bits/stdc++.h>
using namespace std;

int n;
vector<int> adj[500001],leaf;
vector<pair<int,int>> ans;

void dfs(int x, int par) {
    for (auto s : adj[x]) if (s!=par) dfs(s,x);
    if (adj[x].size()==1) leaf.push_back(x);
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin>>n;
    for (int i=0; i<n-1; ++i) {
        int a,b; cin>>a>>b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    for (int i=1; i<=n; ++i) {
        if (adj[i].size()>1) {
            dfs(i,0);
            break;
        }
    }
    if (leaf.size()%2==0) {
        for (int i=0; i<leaf.size()/2; ++i) ans.push_back({leaf[i],leaf[i+leaf.size()/2]});
    } else {
        for (int i=0; i<leaf.size()/2; ++i) ans.push_back({leaf[i],leaf[i+1+leaf.size()/2]});
        ans.push_back({leaf[leaf.size()/2],leaf[0]});
    }
    cout<<ans.size()<<"\n";
    for (auto s : ans) cout<<s.first<<" "<<s.second<<"\n";
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:28:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |         for (int i=0; i<leaf.size()/2; ++i) ans.push_back({leaf[i],leaf[i+leaf.size()/2]});
      |                       ~^~~~~~~~~~~~~~
net.cpp:30:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |         for (int i=0; i<leaf.size()/2; ++i) ans.push_back({leaf[i],leaf[i+1+leaf.size()/2]});
      |                       ~^~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	7 ms	11988 KB	Output is correct
2	Correct	8 ms	11960 KB	Output is correct
3	Correct	7 ms	11988 KB	Output is correct
4	Correct	7 ms	12060 KB	Output is correct
5	Correct	7 ms	11988 KB	Output is correct
6	Correct	7 ms	11984 KB	Output is correct
7	Correct	9 ms	11980 KB	Output is correct
8	Correct	10 ms	11988 KB	Output is correct
9	Correct	9 ms	12068 KB	Output is correct
10	Correct	7 ms	12060 KB	Output is correct
11	Correct	6 ms	11988 KB	Output is correct
12	Correct	7 ms	11988 KB	Output is correct
13	Correct	6 ms	12064 KB	Output is correct
14	Correct	8 ms	11988 KB	Output is correct
15	Correct	7 ms	12052 KB	Output is correct
16	Correct	7 ms	11988 KB	Output is correct
17	Correct	9 ms	12064 KB	Output is correct
18	Correct	7 ms	12116 KB	Output is correct
19	Correct	7 ms	11988 KB	Output is correct
20	Correct	6 ms	11988 KB	Output is correct

Subtask #2
45.0 / 45.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	7 ms	11988 KB	Output is correct
2	Correct	8 ms	11960 KB	Output is correct
3	Correct	7 ms	11988 KB	Output is correct
4	Correct	7 ms	12060 KB	Output is correct
5	Correct	7 ms	11988 KB	Output is correct
6	Correct	7 ms	11984 KB	Output is correct
7	Correct	9 ms	11980 KB	Output is correct
8	Correct	10 ms	11988 KB	Output is correct
9	Correct	9 ms	12068 KB	Output is correct
10	Correct	7 ms	12060 KB	Output is correct
11	Correct	6 ms	11988 KB	Output is correct
12	Correct	7 ms	11988 KB	Output is correct
13	Correct	6 ms	12064 KB	Output is correct
14	Correct	8 ms	11988 KB	Output is correct
15	Correct	7 ms	12052 KB	Output is correct
16	Correct	7 ms	11988 KB	Output is correct
17	Correct	9 ms	12064 KB	Output is correct
18	Correct	7 ms	12116 KB	Output is correct
19	Correct	7 ms	11988 KB	Output is correct
20	Correct	6 ms	11988 KB	Output is correct
21	Correct	7 ms	12064 KB	Output is correct
22	Correct	8 ms	12116 KB	Output is correct
23	Correct	8 ms	12116 KB	Output is correct
24	Correct	10 ms	12116 KB	Output is correct
25	Correct	8 ms	12080 KB	Output is correct
26	Correct	8 ms	12116 KB	Output is correct
27	Correct	9 ms	12088 KB	Output is correct
28	Correct	7 ms	12076 KB	Output is correct
29	Correct	7 ms	12072 KB	Output is correct
30	Correct	7 ms	12068 KB	Output is correct
31	Correct	8 ms	12076 KB	Output is correct
32	Correct	7 ms	11988 KB	Output is correct
33	Correct	7 ms	11984 KB	Output is correct
34	Correct	10 ms	12064 KB	Output is correct
35	Correct	7 ms	11988 KB	Output is correct
36	Correct	7 ms	11988 KB	Output is correct
37	Correct	7 ms	11988 KB	Output is correct
38	Correct	8 ms	12116 KB	Output is correct
39	Correct	7 ms	12064 KB	Output is correct
40	Correct	7 ms	11988 KB	Output is correct
41	Correct	7 ms	12060 KB	Output is correct
42	Correct	8 ms	12068 KB	Output is correct
43	Correct	7 ms	12068 KB	Output is correct
44	Correct	9 ms	11988 KB	Output is correct
45	Correct	7 ms	11988 KB	Output is correct
46	Correct	7 ms	11988 KB	Output is correct
47	Correct	7 ms	11988 KB	Output is correct
48	Correct	7 ms	12040 KB	Output is correct
49	Correct	7 ms	12116 KB	Output is correct
50	Correct	7 ms	12064 KB	Output is correct
51	Correct	7 ms	11988 KB	Output is correct
52	Correct	7 ms	11988 KB	Output is correct
53	Correct	7 ms	12116 KB	Output is correct
54	Correct	7 ms	12068 KB	Output is correct
55	Correct	8 ms	12064 KB	Output is correct
56	Correct	9 ms	12060 KB	Output is correct
57	Correct	9 ms	11988 KB	Output is correct
58	Correct	7 ms	12116 KB	Output is correct

Subtask #3
37.0 / 37.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	7 ms	11988 KB	Output is correct
2	Correct	8 ms	11960 KB	Output is correct
3	Correct	7 ms	11988 KB	Output is correct
4	Correct	7 ms	12060 KB	Output is correct
5	Correct	7 ms	11988 KB	Output is correct
6	Correct	7 ms	11984 KB	Output is correct
7	Correct	9 ms	11980 KB	Output is correct
8	Correct	10 ms	11988 KB	Output is correct
9	Correct	9 ms	12068 KB	Output is correct
10	Correct	7 ms	12060 KB	Output is correct
11	Correct	6 ms	11988 KB	Output is correct
12	Correct	7 ms	11988 KB	Output is correct
13	Correct	6 ms	12064 KB	Output is correct
14	Correct	8 ms	11988 KB	Output is correct
15	Correct	7 ms	12052 KB	Output is correct
16	Correct	7 ms	11988 KB	Output is correct
17	Correct	9 ms	12064 KB	Output is correct
18	Correct	7 ms	12116 KB	Output is correct
19	Correct	7 ms	11988 KB	Output is correct
20	Correct	6 ms	11988 KB	Output is correct
21	Correct	7 ms	12064 KB	Output is correct
22	Correct	8 ms	12116 KB	Output is correct
23	Correct	8 ms	12116 KB	Output is correct
24	Correct	10 ms	12116 KB	Output is correct
25	Correct	8 ms	12080 KB	Output is correct
26	Correct	8 ms	12116 KB	Output is correct
27	Correct	9 ms	12088 KB	Output is correct
28	Correct	7 ms	12076 KB	Output is correct
29	Correct	7 ms	12072 KB	Output is correct
30	Correct	7 ms	12068 KB	Output is correct
31	Correct	8 ms	12076 KB	Output is correct
32	Correct	7 ms	11988 KB	Output is correct
33	Correct	7 ms	11984 KB	Output is correct
34	Correct	10 ms	12064 KB	Output is correct
35	Correct	7 ms	11988 KB	Output is correct
36	Correct	7 ms	11988 KB	Output is correct
37	Correct	7 ms	11988 KB	Output is correct
38	Correct	8 ms	12116 KB	Output is correct
39	Correct	7 ms	12064 KB	Output is correct
40	Correct	7 ms	11988 KB	Output is correct
41	Correct	7 ms	12060 KB	Output is correct
42	Correct	8 ms	12068 KB	Output is correct
43	Correct	7 ms	12068 KB	Output is correct
44	Correct	9 ms	11988 KB	Output is correct
45	Correct	7 ms	11988 KB	Output is correct
46	Correct	7 ms	11988 KB	Output is correct
47	Correct	7 ms	11988 KB	Output is correct
48	Correct	7 ms	12040 KB	Output is correct
49	Correct	7 ms	12116 KB	Output is correct
50	Correct	7 ms	12064 KB	Output is correct
51	Correct	7 ms	11988 KB	Output is correct
52	Correct	7 ms	11988 KB	Output is correct
53	Correct	7 ms	12116 KB	Output is correct
54	Correct	7 ms	12068 KB	Output is correct
55	Correct	8 ms	12064 KB	Output is correct
56	Correct	9 ms	12060 KB	Output is correct
57	Correct	9 ms	11988 KB	Output is correct
58	Correct	7 ms	12116 KB	Output is correct
59	Correct	310 ms	37236 KB	Output is correct
60	Correct	410 ms	40064 KB	Output is correct
61	Correct	7 ms	11988 KB	Output is correct
62	Correct	7 ms	11988 KB	Output is correct
63	Correct	296 ms	34744 KB	Output is correct
64	Correct	10 ms	12572 KB	Output is correct
65	Correct	17 ms	14128 KB	Output is correct
66	Correct	121 ms	30504 KB	Output is correct
67	Correct	455 ms	51160 KB	Output is correct
68	Correct	477 ms	52128 KB	Output is correct
69	Correct	12 ms	13012 KB	Output is correct
70	Correct	74 ms	21744 KB	Output is correct
71	Correct	268 ms	43844 KB	Output is correct
72	Correct	277 ms	42484 KB	Output is correct
73	Correct	71 ms	19316 KB	Output is correct
74	Correct	407 ms	38592 KB	Output is correct
75	Correct	27 ms	15432 KB	Output is correct
76	Correct	294 ms	43352 KB	Output is correct
77	Correct	272 ms	43668 KB	Output is correct
78	Correct	28 ms	15820 KB	Output is correct
79	Correct	440 ms	48788 KB	Output is correct
80	Correct	8 ms	12244 KB	Output is correct
81	Correct	98 ms	21692 KB	Output is correct
82	Correct	364 ms	40924 KB	Output is correct
83	Correct	369 ms	38672 KB	Output is correct
84	Correct	387 ms	38736 KB	Output is correct
85	Correct	387 ms	38708 KB	Output is correct
86	Correct	407 ms	40104 KB	Output is correct
87	Correct	396 ms	40024 KB	Output is correct

Submission #710578

Compilation message

Subtask #1 18.0 / 18.0

Subtask #2 45.0 / 45.0

Subtask #3 37.0 / 37.0

Subtask #1
18.0 / 18.0

Subtask #2
45.0 / 45.0

Subtask #3
37.0 / 37.0