Submission #108712

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
108712	2019-05-01T06:36:19 Z	ckodser	Network (BOI15_net)	C++14	100 / 100	722 ms	53240 KB

#include<bits/stdc++.h>
#define pb push_back
#define x first
#define y second
using namespace std;
const int N = 500005;
int n, ts, st[N];;
vector < int > Adj[N];
void DFS(int v, int p)
{
	st[v] = ts ++;
	for (int &u : Adj[v])
		if (u != p)
			DFS(u, v);
}
bool CMP(int i, int j)
{
	return (st[i] < st[j]);
}
int main()
{
	scanf("%d", &n);
	for (int i = 1; i < n; i++)
	{
		int v, u;
		scanf("%d%d", &v, &u);
		Adj[v].push_back(u);
		Adj[u].push_back(v);
	}
	int id = 1;
	for (int i = 1; i <= n; i++)
		if (Adj[i].size() > 1)
			id = i;
	DFS(id, 0);
	vector < int > vec;
	for (int i = 1; i <= n; i++)
		if ((int)Adj[i].size() == 1)
			vec.push_back(i);
	sort(vec.begin(), vec.end(), CMP);
	int len = (int)vec.size() >> 1;
	printf("%d\n", (int)vec.size() - len);
	for (int i = 0; i < (int)vec.size() - len; i++)
		printf("%d %d\n", vec[i], vec[i + len]);
	return 0;
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:22:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
net.cpp:26:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &v, &u);
   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	13 ms	12032 KB	Output is correct
2	Correct	14 ms	12032 KB	Output is correct
3	Correct	14 ms	12032 KB	Output is correct
4	Correct	14 ms	12120 KB	Output is correct
5	Correct	14 ms	12032 KB	Output is correct
6	Correct	12 ms	12032 KB	Output is correct
7	Correct	16 ms	12032 KB	Output is correct
8	Correct	14 ms	12032 KB	Output is correct
9	Correct	14 ms	12032 KB	Output is correct
10	Correct	14 ms	12032 KB	Output is correct
11	Correct	14 ms	12032 KB	Output is correct
12	Correct	13 ms	12032 KB	Output is correct
13	Correct	13 ms	12160 KB	Output is correct
14	Correct	12 ms	12032 KB	Output is correct
15	Correct	15 ms	12160 KB	Output is correct
16	Correct	12 ms	12032 KB	Output is correct
17	Correct	14 ms	12032 KB	Output is correct
18	Correct	12 ms	12032 KB	Output is correct
19	Correct	12 ms	12032 KB	Output is correct
20	Correct	13 ms	12032 KB	Output is correct

Subtask #2
45.0 / 45.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	13 ms	12032 KB	Output is correct
2	Correct	14 ms	12032 KB	Output is correct
3	Correct	14 ms	12032 KB	Output is correct
4	Correct	14 ms	12120 KB	Output is correct
5	Correct	14 ms	12032 KB	Output is correct
6	Correct	12 ms	12032 KB	Output is correct
7	Correct	16 ms	12032 KB	Output is correct
8	Correct	14 ms	12032 KB	Output is correct
9	Correct	14 ms	12032 KB	Output is correct
10	Correct	14 ms	12032 KB	Output is correct
11	Correct	14 ms	12032 KB	Output is correct
12	Correct	13 ms	12032 KB	Output is correct
13	Correct	13 ms	12160 KB	Output is correct
14	Correct	12 ms	12032 KB	Output is correct
15	Correct	15 ms	12160 KB	Output is correct
16	Correct	12 ms	12032 KB	Output is correct
17	Correct	14 ms	12032 KB	Output is correct
18	Correct	12 ms	12032 KB	Output is correct
19	Correct	12 ms	12032 KB	Output is correct
20	Correct	13 ms	12032 KB	Output is correct
21	Correct	12 ms	12032 KB	Output is correct
22	Correct	16 ms	12160 KB	Output is correct
23	Correct	14 ms	12160 KB	Output is correct
24	Correct	14 ms	12160 KB	Output is correct
25	Correct	14 ms	12160 KB	Output is correct
26	Correct	15 ms	12224 KB	Output is correct
27	Correct	14 ms	12160 KB	Output is correct
28	Correct	14 ms	12160 KB	Output is correct
29	Correct	14 ms	12160 KB	Output is correct
30	Correct	12 ms	12032 KB	Output is correct
31	Correct	17 ms	12160 KB	Output is correct
32	Correct	14 ms	12032 KB	Output is correct
33	Correct	13 ms	12032 KB	Output is correct
34	Correct	13 ms	12032 KB	Output is correct
35	Correct	16 ms	12288 KB	Output is correct
36	Correct	15 ms	12032 KB	Output is correct
37	Correct	18 ms	12160 KB	Output is correct
38	Correct	14 ms	12140 KB	Output is correct
39	Correct	13 ms	12032 KB	Output is correct
40	Correct	12 ms	12032 KB	Output is correct
41	Correct	13 ms	12032 KB	Output is correct
42	Correct	12 ms	12032 KB	Output is correct
43	Correct	15 ms	12160 KB	Output is correct
44	Correct	13 ms	12032 KB	Output is correct
45	Correct	15 ms	12160 KB	Output is correct
46	Correct	13 ms	12160 KB	Output is correct
47	Correct	12 ms	12032 KB	Output is correct
48	Correct	14 ms	12032 KB	Output is correct
49	Correct	15 ms	12160 KB	Output is correct
50	Correct	12 ms	12032 KB	Output is correct
51	Correct	13 ms	12032 KB	Output is correct
52	Correct	13 ms	12160 KB	Output is correct
53	Correct	14 ms	12160 KB	Output is correct
54	Correct	14 ms	12160 KB	Output is correct
55	Correct	16 ms	12160 KB	Output is correct
56	Correct	13 ms	12160 KB	Output is correct
57	Correct	13 ms	12032 KB	Output is correct
58	Correct	16 ms	12160 KB	Output is correct

Subtask #3
37.0 / 37.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	13 ms	12032 KB	Output is correct
2	Correct	14 ms	12032 KB	Output is correct
3	Correct	14 ms	12032 KB	Output is correct
4	Correct	14 ms	12120 KB	Output is correct
5	Correct	14 ms	12032 KB	Output is correct
6	Correct	12 ms	12032 KB	Output is correct
7	Correct	16 ms	12032 KB	Output is correct
8	Correct	14 ms	12032 KB	Output is correct
9	Correct	14 ms	12032 KB	Output is correct
10	Correct	14 ms	12032 KB	Output is correct
11	Correct	14 ms	12032 KB	Output is correct
12	Correct	13 ms	12032 KB	Output is correct
13	Correct	13 ms	12160 KB	Output is correct
14	Correct	12 ms	12032 KB	Output is correct
15	Correct	15 ms	12160 KB	Output is correct
16	Correct	12 ms	12032 KB	Output is correct
17	Correct	14 ms	12032 KB	Output is correct
18	Correct	12 ms	12032 KB	Output is correct
19	Correct	12 ms	12032 KB	Output is correct
20	Correct	13 ms	12032 KB	Output is correct
21	Correct	12 ms	12032 KB	Output is correct
22	Correct	16 ms	12160 KB	Output is correct
23	Correct	14 ms	12160 KB	Output is correct
24	Correct	14 ms	12160 KB	Output is correct
25	Correct	14 ms	12160 KB	Output is correct
26	Correct	15 ms	12224 KB	Output is correct
27	Correct	14 ms	12160 KB	Output is correct
28	Correct	14 ms	12160 KB	Output is correct
29	Correct	14 ms	12160 KB	Output is correct
30	Correct	12 ms	12032 KB	Output is correct
31	Correct	17 ms	12160 KB	Output is correct
32	Correct	14 ms	12032 KB	Output is correct
33	Correct	13 ms	12032 KB	Output is correct
34	Correct	13 ms	12032 KB	Output is correct
35	Correct	16 ms	12288 KB	Output is correct
36	Correct	15 ms	12032 KB	Output is correct
37	Correct	18 ms	12160 KB	Output is correct
38	Correct	14 ms	12140 KB	Output is correct
39	Correct	13 ms	12032 KB	Output is correct
40	Correct	12 ms	12032 KB	Output is correct
41	Correct	13 ms	12032 KB	Output is correct
42	Correct	12 ms	12032 KB	Output is correct
43	Correct	15 ms	12160 KB	Output is correct
44	Correct	13 ms	12032 KB	Output is correct
45	Correct	15 ms	12160 KB	Output is correct
46	Correct	13 ms	12160 KB	Output is correct
47	Correct	12 ms	12032 KB	Output is correct
48	Correct	14 ms	12032 KB	Output is correct
49	Correct	15 ms	12160 KB	Output is correct
50	Correct	12 ms	12032 KB	Output is correct
51	Correct	13 ms	12032 KB	Output is correct
52	Correct	13 ms	12160 KB	Output is correct
53	Correct	14 ms	12160 KB	Output is correct
54	Correct	14 ms	12160 KB	Output is correct
55	Correct	16 ms	12160 KB	Output is correct
56	Correct	13 ms	12160 KB	Output is correct
57	Correct	13 ms	12032 KB	Output is correct
58	Correct	16 ms	12160 KB	Output is correct
59	Correct	540 ms	31844 KB	Output is correct
60	Correct	625 ms	34196 KB	Output is correct
61	Correct	13 ms	12032 KB	Output is correct
62	Correct	14 ms	12004 KB	Output is correct
63	Correct	494 ms	29920 KB	Output is correct
64	Correct	17 ms	12492 KB	Output is correct
65	Correct	29 ms	13688 KB	Output is correct
66	Correct	263 ms	23672 KB	Output is correct
67	Correct	722 ms	53240 KB	Output is correct
68	Correct	654 ms	46040 KB	Output is correct
69	Correct	22 ms	12928 KB	Output is correct
70	Correct	126 ms	19820 KB	Output is correct
71	Correct	511 ms	37012 KB	Output is correct
72	Correct	508 ms	36304 KB	Output is correct
73	Correct	167 ms	18004 KB	Output is correct
74	Correct	682 ms	33048 KB	Output is correct
75	Correct	45 ms	14856 KB	Output is correct
76	Correct	531 ms	36832 KB	Output is correct
77	Correct	524 ms	37076 KB	Output is correct
78	Correct	50 ms	15096 KB	Output is correct
79	Correct	641 ms	40436 KB	Output is correct
80	Correct	16 ms	12288 KB	Output is correct
81	Correct	199 ms	19992 KB	Output is correct
82	Correct	563 ms	35000 KB	Output is correct
83	Correct	673 ms	33140 KB	Output is correct
84	Correct	620 ms	33200 KB	Output is correct
85	Correct	687 ms	33008 KB	Output is correct
86	Correct	593 ms	34148 KB	Output is correct
87	Correct	601 ms	34136 KB	Output is correct

Submission #108712

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