oj.uz

Submission #25877

# Submission time Handle Problem Language Result Execution time Memory
25877 2017-06-24T16:24:47 Z nibnalin Network (BOI15_net) C++14
100 / 100
 723 ms 42512 KB 
#include <iostream>
#include <cstdio>
#include <vector>
#include <cmath>
using namespace std;

const int maxn = int(5e5)+5;

vector<int> graph[maxn], S;

void dfs(int node, int par)
{
	if(int(graph[node].size()) == 1) S.push_back(node);
	for(auto it: graph[node])
	{
		if(it != par) dfs(it, node);
	}
}

int main(void)
{
	int n, u, v;
	scanf("%d", &n);
	for(int i = 1;i < n;i++)
	{
		scanf("%d%d", &u, &v);
		u--, v--;
		graph[u].push_back(v), graph[v].push_back(u);
	}

	dfs(0, -1);

	int res = ceil(int(S.size())/2.0);
	printf("%d\n", res);
	for(int i = 0;i < res;i++)
	{
		printf("%d %d\n", S[i]+1, S[(res+i)%int(S.size())]+1);
	}
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:23:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
net.cpp:26:24: 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 3 ms 13736 KB Output is correct
2 Correct 3 ms 13736 KB Output is correct
3 Correct 0 ms 13736 KB Output is correct
4 Correct 3 ms 13736 KB Output is correct
5 Correct 6 ms 13736 KB Output is correct
6 Correct 6 ms 13736 KB Output is correct
7 Correct 0 ms 13736 KB Output is correct
8 Correct 0 ms 13736 KB Output is correct
9 Correct 0 ms 13736 KB Output is correct
10 Correct 3 ms 13736 KB Output is correct
11 Correct 6 ms 13736 KB Output is correct
12 Correct 6 ms 13736 KB Output is correct
13 Correct 0 ms 13736 KB Output is correct
14 Correct 3 ms 13736 KB Output is correct
15 Correct 3 ms 13736 KB Output is correct
16 Correct 0 ms 13736 KB Output is correct
17 Correct 0 ms 13736 KB Output is correct
18 Correct 3 ms 13736 KB Output is correct
19 Correct 3 ms 13736 KB Output is correct
20 Correct 6 ms 13736 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 13736 KB Output is correct
2 Correct 3 ms 13736 KB Output is correct
3 Correct 0 ms 13736 KB Output is correct
4 Correct 3 ms 13736 KB Output is correct
5 Correct 6 ms 13736 KB Output is correct
6 Correct 6 ms 13736 KB Output is correct
7 Correct 0 ms 13736 KB Output is correct
8 Correct 0 ms 13736 KB Output is correct
9 Correct 0 ms 13736 KB Output is correct
10 Correct 3 ms 13736 KB Output is correct
11 Correct 6 ms 13736 KB Output is correct
12 Correct 6 ms 13736 KB Output is correct
13 Correct 0 ms 13736 KB Output is correct
14 Correct 3 ms 13736 KB Output is correct
15 Correct 3 ms 13736 KB Output is correct
16 Correct 0 ms 13736 KB Output is correct
17 Correct 0 ms 13736 KB Output is correct
18 Correct 3 ms 13736 KB Output is correct
19 Correct 3 ms 13736 KB Output is correct
20 Correct 6 ms 13736 KB Output is correct
21 Correct 3 ms 13736 KB Output is correct
22 Correct 3 ms 13868 KB Output is correct
23 Correct 6 ms 13868 KB Output is correct
24 Correct 6 ms 13868 KB Output is correct
25 Correct 3 ms 13868 KB Output is correct
26 Correct 0 ms 13868 KB Output is correct
27 Correct 6 ms 13868 KB Output is correct
28 Correct 0 ms 13868 KB Output is correct
29 Correct 3 ms 13868 KB Output is correct
30 Correct 0 ms 13736 KB Output is correct
31 Correct 3 ms 13868 KB Output is correct
32 Correct 0 ms 13736 KB Output is correct
33 Correct 3 ms 13736 KB Output is correct
34 Correct 3 ms 13736 KB Output is correct
35 Correct 3 ms 13736 KB Output is correct
36 Correct 3 ms 13736 KB Output is correct
37 Correct 6 ms 13736 KB Output is correct
38 Correct 6 ms 13736 KB Output is correct
39 Correct 0 ms 13736 KB Output is correct
40 Correct 0 ms 13736 KB Output is correct
41 Correct 0 ms 13736 KB Output is correct
42 Correct 3 ms 13736 KB Output is correct
43 Correct 6 ms 13736 KB Output is correct
44 Correct 3 ms 13736 KB Output is correct
45 Correct 3 ms 13736 KB Output is correct
46 Correct 3 ms 13736 KB Output is correct
47 Correct 3 ms 13736 KB Output is correct
48 Correct 0 ms 13736 KB Output is correct
49 Correct 3 ms 13736 KB Output is correct
50 Correct 3 ms 13736 KB Output is correct
51 Correct 3 ms 13736 KB Output is correct
52 Correct 9 ms 13736 KB Output is correct
53 Correct 0 ms 13736 KB Output is correct
54 Correct 3 ms 13736 KB Output is correct
55 Correct 6 ms 13736 KB Output is correct
56 Correct 3 ms 13736 KB Output is correct
57 Correct 3 ms 13736 KB Output is correct
58 Correct 0 ms 13868 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 13736 KB Output is correct
2 Correct 3 ms 13736 KB Output is correct
3 Correct 0 ms 13736 KB Output is correct
4 Correct 3 ms 13736 KB Output is correct
5 Correct 6 ms 13736 KB Output is correct
6 Correct 6 ms 13736 KB Output is correct
7 Correct 0 ms 13736 KB Output is correct
8 Correct 0 ms 13736 KB Output is correct
9 Correct 0 ms 13736 KB Output is correct
10 Correct 3 ms 13736 KB Output is correct
11 Correct 6 ms 13736 KB Output is correct
12 Correct 6 ms 13736 KB Output is correct
13 Correct 0 ms 13736 KB Output is correct
14 Correct 3 ms 13736 KB Output is correct
15 Correct 3 ms 13736 KB Output is correct
16 Correct 0 ms 13736 KB Output is correct
17 Correct 0 ms 13736 KB Output is correct
18 Correct 3 ms 13736 KB Output is correct
19 Correct 3 ms 13736 KB Output is correct
20 Correct 6 ms 13736 KB Output is correct
21 Correct 3 ms 13736 KB Output is correct
22 Correct 3 ms 13868 KB Output is correct
23 Correct 6 ms 13868 KB Output is correct
24 Correct 6 ms 13868 KB Output is correct
25 Correct 3 ms 13868 KB Output is correct
26 Correct 0 ms 13868 KB Output is correct
27 Correct 6 ms 13868 KB Output is correct
28 Correct 0 ms 13868 KB Output is correct
29 Correct 3 ms 13868 KB Output is correct
30 Correct 0 ms 13736 KB Output is correct
31 Correct 3 ms 13868 KB Output is correct
32 Correct 0 ms 13736 KB Output is correct
33 Correct 3 ms 13736 KB Output is correct
34 Correct 3 ms 13736 KB Output is correct
35 Correct 3 ms 13736 KB Output is correct
36 Correct 3 ms 13736 KB Output is correct
37 Correct 6 ms 13736 KB Output is correct
38 Correct 6 ms 13736 KB Output is correct
39 Correct 0 ms 13736 KB Output is correct
40 Correct 0 ms 13736 KB Output is correct
41 Correct 0 ms 13736 KB Output is correct
42 Correct 3 ms 13736 KB Output is correct
43 Correct 6 ms 13736 KB Output is correct
44 Correct 3 ms 13736 KB Output is correct
45 Correct 3 ms 13736 KB Output is correct
46 Correct 3 ms 13736 KB Output is correct
47 Correct 3 ms 13736 KB Output is correct
48 Correct 0 ms 13736 KB Output is correct
49 Correct 3 ms 13736 KB Output is correct
50 Correct 3 ms 13736 KB Output is correct
51 Correct 3 ms 13736 KB Output is correct
52 Correct 9 ms 13736 KB Output is correct
53 Correct 0 ms 13736 KB Output is correct
54 Correct 3 ms 13736 KB Output is correct
55 Correct 6 ms 13736 KB Output is correct
56 Correct 3 ms 13736 KB Output is correct
57 Correct 3 ms 13736 KB Output is correct
58 Correct 0 ms 13868 KB Output is correct
59 Correct 519 ms 31984 KB Output is correct
60 Correct 723 ms 33248 KB Output is correct
61 Correct 0 ms 13736 KB Output is correct
62 Correct 0 ms 13736 KB Output is correct
63 Correct 393 ms 29908 KB Output is correct
64 Correct 6 ms 13972 KB Output is correct
65 Correct 13 ms 15252 KB Output is correct
66 Correct 106 ms 27248 KB Output is correct
67 Correct 636 ms 41752 KB Output is correct
68 Correct 679 ms 42512 KB Output is correct
69 Correct 6 ms 14472 KB Output is correct
70 Correct 106 ms 21892 KB Output is correct
71 Correct 473 ms 35588 KB Output is correct
72 Correct 423 ms 35588 KB Output is correct
73 Correct 109 ms 19092 KB Output is correct
74 Correct 606 ms 31532 KB Output is correct
75 Correct 33 ms 16200 KB Output is correct
76 Correct 373 ms 34572 KB Output is correct
77 Correct 313 ms 34572 KB Output is correct
78 Correct 19 ms 16212 KB Output is correct
79 Correct 629 ms 40008 KB Output is correct
80 Correct 6 ms 13868 KB Output is correct
81 Correct 109 ms 20764 KB Output is correct
82 Correct 469 ms 33816 KB Output is correct
83 Correct 503 ms 31532 KB Output is correct
84 Correct 506 ms 31532 KB Output is correct
85 Correct 499 ms 31532 KB Output is correct
86 Correct 586 ms 33252 KB Output is correct
87 Correct 609 ms 33252 KB Output is correct