Submission #59637

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
59637	2018-07-22T20:08:06 Z	IvanC	Network (BOI15_net)	C++17	100 / 100	754 ms	153032 KB

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

const int MAXN = 5*1e5 + 10;

vector<int> grafo[MAXN],folhas;
int N;

void dfs(int v,int p){
	if(grafo[v].size() == 1) folhas.push_back(v);
	for(int u : grafo[v]) if(u != p) dfs(u,v);
}

int main(){

	scanf("%d",&N);
	for(int i = 1;i<N;i++){
		int u,v;
		scanf("%d %d",&u,&v);
		grafo[u].push_back(v);
		grafo[v].push_back(u);
	}

	dfs(1,-1);

	int ans = (folhas.size() + 1)/2;
	int delta = (folhas.size())/2;
	printf("%d\n",ans);
	for(int i = 0;i<ans;i++){
		printf("%d %d\n",folhas[i],folhas[i + delta]);
	}

	return 0;
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:16:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&N);
  ~~~~~^~~~~~~~~
net.cpp:19:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&u,&v);
   ~~~~~^~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	14 ms	12024 KB	Output is correct
2	Correct	12 ms	12136 KB	Output is correct
3	Correct	16 ms	12172 KB	Output is correct
4	Correct	12 ms	12172 KB	Output is correct
5	Correct	15 ms	12172 KB	Output is correct
6	Correct	14 ms	12172 KB	Output is correct
7	Correct	14 ms	12172 KB	Output is correct
8	Correct	12 ms	12268 KB	Output is correct
9	Correct	16 ms	12268 KB	Output is correct
10	Correct	15 ms	12348 KB	Output is correct
11	Correct	12 ms	12380 KB	Output is correct
12	Correct	16 ms	12380 KB	Output is correct
13	Correct	16 ms	12392 KB	Output is correct
14	Correct	14 ms	12392 KB	Output is correct
15	Correct	16 ms	12392 KB	Output is correct
16	Correct	15 ms	12392 KB	Output is correct
17	Correct	16 ms	12392 KB	Output is correct
18	Correct	14 ms	12392 KB	Output is correct
19	Correct	14 ms	12392 KB	Output is correct
20	Correct	14 ms	12392 KB	Output is correct

Subtask #2
45.0 / 45.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	14 ms	12024 KB	Output is correct
2	Correct	12 ms	12136 KB	Output is correct
3	Correct	16 ms	12172 KB	Output is correct
4	Correct	12 ms	12172 KB	Output is correct
5	Correct	15 ms	12172 KB	Output is correct
6	Correct	14 ms	12172 KB	Output is correct
7	Correct	14 ms	12172 KB	Output is correct
8	Correct	12 ms	12268 KB	Output is correct
9	Correct	16 ms	12268 KB	Output is correct
10	Correct	15 ms	12348 KB	Output is correct
11	Correct	12 ms	12380 KB	Output is correct
12	Correct	16 ms	12380 KB	Output is correct
13	Correct	16 ms	12392 KB	Output is correct
14	Correct	14 ms	12392 KB	Output is correct
15	Correct	16 ms	12392 KB	Output is correct
16	Correct	15 ms	12392 KB	Output is correct
17	Correct	16 ms	12392 KB	Output is correct
18	Correct	14 ms	12392 KB	Output is correct
19	Correct	14 ms	12392 KB	Output is correct
20	Correct	14 ms	12392 KB	Output is correct
21	Correct	17 ms	12392 KB	Output is correct
22	Correct	17 ms	12472 KB	Output is correct
23	Correct	14 ms	12508 KB	Output is correct
24	Correct	13 ms	12508 KB	Output is correct
25	Correct	18 ms	12580 KB	Output is correct
26	Correct	16 ms	12612 KB	Output is correct
27	Correct	18 ms	12624 KB	Output is correct
28	Correct	20 ms	12624 KB	Output is correct
29	Correct	18 ms	12664 KB	Output is correct
30	Correct	13 ms	12664 KB	Output is correct
31	Correct	16 ms	12728 KB	Output is correct
32	Correct	15 ms	12728 KB	Output is correct
33	Correct	16 ms	12728 KB	Output is correct
34	Correct	15 ms	12728 KB	Output is correct
35	Correct	18 ms	12728 KB	Output is correct
36	Correct	12 ms	12728 KB	Output is correct
37	Correct	16 ms	12728 KB	Output is correct
38	Correct	16 ms	12732 KB	Output is correct
39	Correct	16 ms	12732 KB	Output is correct
40	Correct	15 ms	12732 KB	Output is correct
41	Correct	13 ms	12732 KB	Output is correct
42	Correct	12 ms	12732 KB	Output is correct
43	Correct	15 ms	12732 KB	Output is correct
44	Correct	13 ms	12732 KB	Output is correct
45	Correct	13 ms	12732 KB	Output is correct
46	Correct	14 ms	12732 KB	Output is correct
47	Correct	14 ms	12732 KB	Output is correct
48	Correct	12 ms	12732 KB	Output is correct
49	Correct	13 ms	12832 KB	Output is correct
50	Correct	12 ms	12832 KB	Output is correct
51	Correct	13 ms	12832 KB	Output is correct
52	Correct	13 ms	12832 KB	Output is correct
53	Correct	13 ms	12832 KB	Output is correct
54	Correct	12 ms	12832 KB	Output is correct
55	Correct	13 ms	12832 KB	Output is correct
56	Correct	13 ms	12832 KB	Output is correct
57	Correct	12 ms	12832 KB	Output is correct
58	Correct	16 ms	12836 KB	Output is correct

Subtask #3
37.0 / 37.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	14 ms	12024 KB	Output is correct
2	Correct	12 ms	12136 KB	Output is correct
3	Correct	16 ms	12172 KB	Output is correct
4	Correct	12 ms	12172 KB	Output is correct
5	Correct	15 ms	12172 KB	Output is correct
6	Correct	14 ms	12172 KB	Output is correct
7	Correct	14 ms	12172 KB	Output is correct
8	Correct	12 ms	12268 KB	Output is correct
9	Correct	16 ms	12268 KB	Output is correct
10	Correct	15 ms	12348 KB	Output is correct
11	Correct	12 ms	12380 KB	Output is correct
12	Correct	16 ms	12380 KB	Output is correct
13	Correct	16 ms	12392 KB	Output is correct
14	Correct	14 ms	12392 KB	Output is correct
15	Correct	16 ms	12392 KB	Output is correct
16	Correct	15 ms	12392 KB	Output is correct
17	Correct	16 ms	12392 KB	Output is correct
18	Correct	14 ms	12392 KB	Output is correct
19	Correct	14 ms	12392 KB	Output is correct
20	Correct	14 ms	12392 KB	Output is correct
21	Correct	17 ms	12392 KB	Output is correct
22	Correct	17 ms	12472 KB	Output is correct
23	Correct	14 ms	12508 KB	Output is correct
24	Correct	13 ms	12508 KB	Output is correct
25	Correct	18 ms	12580 KB	Output is correct
26	Correct	16 ms	12612 KB	Output is correct
27	Correct	18 ms	12624 KB	Output is correct
28	Correct	20 ms	12624 KB	Output is correct
29	Correct	18 ms	12664 KB	Output is correct
30	Correct	13 ms	12664 KB	Output is correct
31	Correct	16 ms	12728 KB	Output is correct
32	Correct	15 ms	12728 KB	Output is correct
33	Correct	16 ms	12728 KB	Output is correct
34	Correct	15 ms	12728 KB	Output is correct
35	Correct	18 ms	12728 KB	Output is correct
36	Correct	12 ms	12728 KB	Output is correct
37	Correct	16 ms	12728 KB	Output is correct
38	Correct	16 ms	12732 KB	Output is correct
39	Correct	16 ms	12732 KB	Output is correct
40	Correct	15 ms	12732 KB	Output is correct
41	Correct	13 ms	12732 KB	Output is correct
42	Correct	12 ms	12732 KB	Output is correct
43	Correct	15 ms	12732 KB	Output is correct
44	Correct	13 ms	12732 KB	Output is correct
45	Correct	13 ms	12732 KB	Output is correct
46	Correct	14 ms	12732 KB	Output is correct
47	Correct	14 ms	12732 KB	Output is correct
48	Correct	12 ms	12732 KB	Output is correct
49	Correct	13 ms	12832 KB	Output is correct
50	Correct	12 ms	12832 KB	Output is correct
51	Correct	13 ms	12832 KB	Output is correct
52	Correct	13 ms	12832 KB	Output is correct
53	Correct	13 ms	12832 KB	Output is correct
54	Correct	12 ms	12832 KB	Output is correct
55	Correct	13 ms	12832 KB	Output is correct
56	Correct	13 ms	12832 KB	Output is correct
57	Correct	12 ms	12832 KB	Output is correct
58	Correct	16 ms	12836 KB	Output is correct
59	Correct	549 ms	36652 KB	Output is correct
60	Correct	558 ms	45432 KB	Output is correct
61	Correct	13 ms	45432 KB	Output is correct
62	Correct	12 ms	45432 KB	Output is correct
63	Correct	402 ms	46792 KB	Output is correct
64	Correct	16 ms	46792 KB	Output is correct
65	Correct	27 ms	46792 KB	Output is correct
66	Correct	199 ms	46912 KB	Output is correct
67	Correct	661 ms	68084 KB	Output is correct
68	Correct	723 ms	75688 KB	Output is correct
69	Correct	25 ms	75688 KB	Output is correct
70	Correct	163 ms	75688 KB	Output is correct
71	Correct	406 ms	78476 KB	Output is correct
72	Correct	396 ms	84080 KB	Output is correct
73	Correct	143 ms	84080 KB	Output is correct
74	Correct	611 ms	89128 KB	Output is correct
75	Correct	55 ms	89128 KB	Output is correct
76	Correct	456 ms	100164 KB	Output is correct
77	Correct	428 ms	107032 KB	Output is correct
78	Correct	52 ms	107032 KB	Output is correct
79	Correct	647 ms	117856 KB	Output is correct
80	Correct	16 ms	117856 KB	Output is correct
81	Correct	141 ms	117856 KB	Output is correct
82	Correct	474 ms	120764 KB	Output is correct
83	Correct	665 ms	125388 KB	Output is correct
84	Correct	754 ms	132116 KB	Output is correct
85	Correct	570 ms	138884 KB	Output is correct
86	Correct	700 ms	146308 KB	Output is correct
87	Correct	709 ms	153032 KB	Output is correct

Submission #59637

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