Submission #672875

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
672875	2022-12-18T18:14:52 Z	iosif_andrei_	Network (BOI15_net)	C++14	100 / 100	632 ms	65612 KB

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

int n;
vector <int> g[500001];
vector <int> v; // leaves
bitset <500001> f;

void dfs(int nod)
{
    f[nod] = true;

    if (g[nod].size() == 1)
        v.push_back(nod);

    for (auto& i : g[nod])
        if (!f[i])
            dfs(i);
}

int main() {
    
    cin >> n;

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

    int root;
    for (int i = 1; i <= n; i++)
        if (g[i].size() == 1)
        {
            root = i;
            break;
        }

    dfs(root);

    cout << (v.size() + 1) / 2 << '\n';

    int i, j;

    if (v.size() % 2)
    {
        i = 0, j = v.size() / 2;

        while (i < v.size() / 2)
        {
            cout << v[i] << ' ' << v[j] << '\n';
            i++, j++;
        }

        cout << v.back() << ' ' << v[0];
    }
    else
    {
        i = 0, j = v.size() / 2;

        while (i < v.size() / 2)
        {
            cout << v[i] << ' ' << v[j] << '\n';
            i++, j++;
        }
    }

    return 0;
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:51:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |         while (i < v.size() / 2)
      |                ~~^~~~~~~~~~~~~~
net.cpp:63:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |         while (i < v.size() / 2)
      |                ~~^~~~~~~~~~~~~~
net.cpp:41:8: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
   41 |     dfs(root);
      |     ~~~^~~~~~

Subtask #1
18.0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	7 ms	12032 KB	Output is correct
2	Correct	6 ms	11988 KB	Output is correct
3	Correct	6 ms	11932 KB	Output is correct
4	Correct	6 ms	12040 KB	Output is correct
5	Correct	6 ms	11988 KB	Output is correct
6	Correct	6 ms	12052 KB	Output is correct
7	Correct	6 ms	11988 KB	Output is correct
8	Correct	6 ms	12044 KB	Output is correct
9	Correct	6 ms	11988 KB	Output is correct
10	Correct	6 ms	11992 KB	Output is correct
11	Correct	6 ms	11988 KB	Output is correct
12	Correct	6 ms	12048 KB	Output is correct
13	Correct	6 ms	11988 KB	Output is correct
14	Correct	6 ms	11988 KB	Output is correct
15	Correct	7 ms	11988 KB	Output is correct
16	Correct	6 ms	11988 KB	Output is correct
17	Correct	6 ms	11944 KB	Output is correct
18	Correct	6 ms	11988 KB	Output is correct
19	Correct	6 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	12032 KB	Output is correct
2	Correct	6 ms	11988 KB	Output is correct
3	Correct	6 ms	11932 KB	Output is correct
4	Correct	6 ms	12040 KB	Output is correct
5	Correct	6 ms	11988 KB	Output is correct
6	Correct	6 ms	12052 KB	Output is correct
7	Correct	6 ms	11988 KB	Output is correct
8	Correct	6 ms	12044 KB	Output is correct
9	Correct	6 ms	11988 KB	Output is correct
10	Correct	6 ms	11992 KB	Output is correct
11	Correct	6 ms	11988 KB	Output is correct
12	Correct	6 ms	12048 KB	Output is correct
13	Correct	6 ms	11988 KB	Output is correct
14	Correct	6 ms	11988 KB	Output is correct
15	Correct	7 ms	11988 KB	Output is correct
16	Correct	6 ms	11988 KB	Output is correct
17	Correct	6 ms	11944 KB	Output is correct
18	Correct	6 ms	11988 KB	Output is correct
19	Correct	6 ms	11988 KB	Output is correct
20	Correct	6 ms	11988 KB	Output is correct
21	Correct	7 ms	11988 KB	Output is correct
22	Correct	8 ms	12128 KB	Output is correct
23	Correct	7 ms	12108 KB	Output is correct
24	Correct	7 ms	12116 KB	Output is correct
25	Correct	9 ms	12060 KB	Output is correct
26	Correct	9 ms	12116 KB	Output is correct
27	Correct	8 ms	12116 KB	Output is correct
28	Correct	7 ms	12116 KB	Output is correct
29	Correct	7 ms	12116 KB	Output is correct
30	Correct	6 ms	12048 KB	Output is correct
31	Correct	8 ms	12116 KB	Output is correct
32	Correct	6 ms	11988 KB	Output is correct
33	Correct	6 ms	11988 KB	Output is correct
34	Correct	7 ms	11988 KB	Output is correct
35	Correct	6 ms	12000 KB	Output is correct
36	Correct	6 ms	12052 KB	Output is correct
37	Correct	7 ms	12056 KB	Output is correct
38	Correct	7 ms	12116 KB	Output is correct
39	Correct	6 ms	12048 KB	Output is correct
40	Correct	7 ms	11988 KB	Output is correct
41	Correct	6 ms	11988 KB	Output is correct
42	Correct	7 ms	11988 KB	Output is correct
43	Correct	7 ms	12048 KB	Output is correct
44	Correct	8 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	6 ms	11988 KB	Output is correct
48	Correct	6 ms	12048 KB	Output is correct
49	Correct	7 ms	12052 KB	Output is correct
50	Correct	6 ms	11988 KB	Output is correct
51	Correct	6 ms	11988 KB	Output is correct
52	Correct	7 ms	11988 KB	Output is correct
53	Correct	7 ms	11988 KB	Output is correct
54	Correct	7 ms	12044 KB	Output is correct
55	Correct	7 ms	12044 KB	Output is correct
56	Correct	6 ms	11988 KB	Output is correct
57	Correct	8 ms	11988 KB	Output is correct
58	Correct	8 ms	12056 KB	Output is correct

Subtask #3
37.0 / 37.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	7 ms	12032 KB	Output is correct
2	Correct	6 ms	11988 KB	Output is correct
3	Correct	6 ms	11932 KB	Output is correct
4	Correct	6 ms	12040 KB	Output is correct
5	Correct	6 ms	11988 KB	Output is correct
6	Correct	6 ms	12052 KB	Output is correct
7	Correct	6 ms	11988 KB	Output is correct
8	Correct	6 ms	12044 KB	Output is correct
9	Correct	6 ms	11988 KB	Output is correct
10	Correct	6 ms	11992 KB	Output is correct
11	Correct	6 ms	11988 KB	Output is correct
12	Correct	6 ms	12048 KB	Output is correct
13	Correct	6 ms	11988 KB	Output is correct
14	Correct	6 ms	11988 KB	Output is correct
15	Correct	7 ms	11988 KB	Output is correct
16	Correct	6 ms	11988 KB	Output is correct
17	Correct	6 ms	11944 KB	Output is correct
18	Correct	6 ms	11988 KB	Output is correct
19	Correct	6 ms	11988 KB	Output is correct
20	Correct	6 ms	11988 KB	Output is correct
21	Correct	7 ms	11988 KB	Output is correct
22	Correct	8 ms	12128 KB	Output is correct
23	Correct	7 ms	12108 KB	Output is correct
24	Correct	7 ms	12116 KB	Output is correct
25	Correct	9 ms	12060 KB	Output is correct
26	Correct	9 ms	12116 KB	Output is correct
27	Correct	8 ms	12116 KB	Output is correct
28	Correct	7 ms	12116 KB	Output is correct
29	Correct	7 ms	12116 KB	Output is correct
30	Correct	6 ms	12048 KB	Output is correct
31	Correct	8 ms	12116 KB	Output is correct
32	Correct	6 ms	11988 KB	Output is correct
33	Correct	6 ms	11988 KB	Output is correct
34	Correct	7 ms	11988 KB	Output is correct
35	Correct	6 ms	12000 KB	Output is correct
36	Correct	6 ms	12052 KB	Output is correct
37	Correct	7 ms	12056 KB	Output is correct
38	Correct	7 ms	12116 KB	Output is correct
39	Correct	6 ms	12048 KB	Output is correct
40	Correct	7 ms	11988 KB	Output is correct
41	Correct	6 ms	11988 KB	Output is correct
42	Correct	7 ms	11988 KB	Output is correct
43	Correct	7 ms	12048 KB	Output is correct
44	Correct	8 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	6 ms	11988 KB	Output is correct
48	Correct	6 ms	12048 KB	Output is correct
49	Correct	7 ms	12052 KB	Output is correct
50	Correct	6 ms	11988 KB	Output is correct
51	Correct	6 ms	11988 KB	Output is correct
52	Correct	7 ms	11988 KB	Output is correct
53	Correct	7 ms	11988 KB	Output is correct
54	Correct	7 ms	12044 KB	Output is correct
55	Correct	7 ms	12044 KB	Output is correct
56	Correct	6 ms	11988 KB	Output is correct
57	Correct	8 ms	11988 KB	Output is correct
58	Correct	8 ms	12056 KB	Output is correct
59	Correct	462 ms	36052 KB	Output is correct
60	Correct	555 ms	38900 KB	Output is correct
61	Correct	7 ms	11988 KB	Output is correct
62	Correct	7 ms	12052 KB	Output is correct
63	Correct	401 ms	33552 KB	Output is correct
64	Correct	9 ms	12372 KB	Output is correct
65	Correct	23 ms	14320 KB	Output is correct
66	Correct	173 ms	29968 KB	Output is correct
67	Correct	599 ms	65612 KB	Output is correct
68	Correct	632 ms	53016 KB	Output is correct
69	Correct	16 ms	12884 KB	Output is correct
70	Correct	138 ms	21184 KB	Output is correct
71	Correct	436 ms	41916 KB	Output is correct
72	Correct	437 ms	40672 KB	Output is correct
73	Correct	121 ms	19020 KB	Output is correct
74	Correct	540 ms	37720 KB	Output is correct
75	Correct	48 ms	15140 KB	Output is correct
76	Correct	461 ms	41536 KB	Output is correct
77	Correct	436 ms	41708 KB	Output is correct
78	Correct	46 ms	15480 KB	Output is correct
79	Correct	593 ms	55384 KB	Output is correct
80	Correct	9 ms	12244 KB	Output is correct
81	Correct	145 ms	21260 KB	Output is correct
82	Correct	489 ms	39532 KB	Output is correct
83	Correct	543 ms	37708 KB	Output is correct
84	Correct	552 ms	37756 KB	Output is correct
85	Correct	536 ms	37676 KB	Output is correct
86	Correct	535 ms	38776 KB	Output is correct
87	Correct	535 ms	38824 KB	Output is correct

Submission #672875

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