Submission #24944

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
24944	2017-06-18T00:29:35 Z	RezwanArefin01	Network (BOI15_net)	C++14	100 / 100	623 ms	42508 KB

//Bismillahir Rahmanir Rahim
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> ii;
const int maxn = 5e5;
vector<int> adj[maxn], lef; 
void dfs(int u, int par){
	for(int v : adj[u]) if(v - par) dfs(v, u);
	if(adj[u].size() == 1) lef.push_back(u);
}
int main(int argc, char const *argv[]) {
#ifdef LOCAL_TESTING
	freopen("in", "r", stdin);
#endif
	int n; scanf("%d", &n);
	for(int i=0; i<n-1; i++) {
		int u, v; 
		scanf("%d %d", &u, &v);
		adj[u].push_back(v); 
		adj[v].push_back(u); 
	}
	for(int i=1; i<=n; i++) if(adj[i].size() > 1) {
		dfs(i, 0); break;
	}
	int sz = int((lef.size()+1)/2); 
	printf("%d\n", sz);
	for(int i=0; i<sz; i++) {
		printf("%d %d\n", lef[i], lef[i + lef.size()/2]);
	}
}

Compilation message

net.cpp: In function 'int main(int, const char**)':
net.cpp:16:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  int n; scanf("%d", &n);
                        ^
net.cpp:19:25: 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	0 ms	13736 KB	Output is correct
3	Correct	3 ms	13736 KB	Output is correct
4	Correct	0 ms	13736 KB	Output is correct
5	Correct	0 ms	13736 KB	Output is correct
6	Correct	0 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	3 ms	13736 KB	Output is correct
10	Correct	6 ms	13736 KB	Output is correct
11	Correct	0 ms	13736 KB	Output is correct
12	Correct	0 ms	13736 KB	Output is correct
13	Correct	0 ms	13736 KB	Output is correct
14	Correct	0 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	3 ms	13736 KB	Output is correct
18	Correct	6 ms	13736 KB	Output is correct
19	Correct	0 ms	13736 KB	Output is correct
20	Correct	0 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	0 ms	13736 KB	Output is correct
3	Correct	3 ms	13736 KB	Output is correct
4	Correct	0 ms	13736 KB	Output is correct
5	Correct	0 ms	13736 KB	Output is correct
6	Correct	0 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	3 ms	13736 KB	Output is correct
10	Correct	6 ms	13736 KB	Output is correct
11	Correct	0 ms	13736 KB	Output is correct
12	Correct	0 ms	13736 KB	Output is correct
13	Correct	0 ms	13736 KB	Output is correct
14	Correct	0 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	3 ms	13736 KB	Output is correct
18	Correct	6 ms	13736 KB	Output is correct
19	Correct	0 ms	13736 KB	Output is correct
20	Correct	0 ms	13736 KB	Output is correct
21	Correct	6 ms	13736 KB	Output is correct
22	Correct	3 ms	13868 KB	Output is correct
23	Correct	3 ms	13868 KB	Output is correct
24	Correct	0 ms	13868 KB	Output is correct
25	Correct	3 ms	13868 KB	Output is correct
26	Correct	6 ms	13868 KB	Output is correct
27	Correct	3 ms	13868 KB	Output is correct
28	Correct	0 ms	13868 KB	Output is correct
29	Correct	0 ms	13868 KB	Output is correct
30	Correct	3 ms	13736 KB	Output is correct
31	Correct	0 ms	13868 KB	Output is correct
32	Correct	3 ms	13736 KB	Output is correct
33	Correct	3 ms	13736 KB	Output is correct
34	Correct	0 ms	13736 KB	Output is correct
35	Correct	6 ms	13736 KB	Output is correct
36	Correct	0 ms	13736 KB	Output is correct
37	Correct	0 ms	13736 KB	Output is correct
38	Correct	3 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	3 ms	13736 KB	Output is correct
42	Correct	0 ms	13736 KB	Output is correct
43	Correct	0 ms	13736 KB	Output is correct
44	Correct	0 ms	13736 KB	Output is correct
45	Correct	3 ms	13736 KB	Output is correct
46	Correct	6 ms	13736 KB	Output is correct
47	Correct	0 ms	13736 KB	Output is correct
48	Correct	0 ms	13736 KB	Output is correct
49	Correct	0 ms	13736 KB	Output is correct
50	Correct	0 ms	13736 KB	Output is correct
51	Correct	0 ms	13736 KB	Output is correct
52	Correct	6 ms	13736 KB	Output is correct
53	Correct	3 ms	13736 KB	Output is correct
54	Correct	3 ms	13736 KB	Output is correct
55	Correct	3 ms	13736 KB	Output is correct
56	Correct	3 ms	13736 KB	Output is correct
57	Correct	0 ms	13736 KB	Output is correct
58	Correct	3 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	0 ms	13736 KB	Output is correct
3	Correct	3 ms	13736 KB	Output is correct
4	Correct	0 ms	13736 KB	Output is correct
5	Correct	0 ms	13736 KB	Output is correct
6	Correct	0 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	3 ms	13736 KB	Output is correct
10	Correct	6 ms	13736 KB	Output is correct
11	Correct	0 ms	13736 KB	Output is correct
12	Correct	0 ms	13736 KB	Output is correct
13	Correct	0 ms	13736 KB	Output is correct
14	Correct	0 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	3 ms	13736 KB	Output is correct
18	Correct	6 ms	13736 KB	Output is correct
19	Correct	0 ms	13736 KB	Output is correct
20	Correct	0 ms	13736 KB	Output is correct
21	Correct	6 ms	13736 KB	Output is correct
22	Correct	3 ms	13868 KB	Output is correct
23	Correct	3 ms	13868 KB	Output is correct
24	Correct	0 ms	13868 KB	Output is correct
25	Correct	3 ms	13868 KB	Output is correct
26	Correct	6 ms	13868 KB	Output is correct
27	Correct	3 ms	13868 KB	Output is correct
28	Correct	0 ms	13868 KB	Output is correct
29	Correct	0 ms	13868 KB	Output is correct
30	Correct	3 ms	13736 KB	Output is correct
31	Correct	0 ms	13868 KB	Output is correct
32	Correct	3 ms	13736 KB	Output is correct
33	Correct	3 ms	13736 KB	Output is correct
34	Correct	0 ms	13736 KB	Output is correct
35	Correct	6 ms	13736 KB	Output is correct
36	Correct	0 ms	13736 KB	Output is correct
37	Correct	0 ms	13736 KB	Output is correct
38	Correct	3 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	3 ms	13736 KB	Output is correct
42	Correct	0 ms	13736 KB	Output is correct
43	Correct	0 ms	13736 KB	Output is correct
44	Correct	0 ms	13736 KB	Output is correct
45	Correct	3 ms	13736 KB	Output is correct
46	Correct	6 ms	13736 KB	Output is correct
47	Correct	0 ms	13736 KB	Output is correct
48	Correct	0 ms	13736 KB	Output is correct
49	Correct	0 ms	13736 KB	Output is correct
50	Correct	0 ms	13736 KB	Output is correct
51	Correct	0 ms	13736 KB	Output is correct
52	Correct	6 ms	13736 KB	Output is correct
53	Correct	3 ms	13736 KB	Output is correct
54	Correct	3 ms	13736 KB	Output is correct
55	Correct	3 ms	13736 KB	Output is correct
56	Correct	3 ms	13736 KB	Output is correct
57	Correct	0 ms	13736 KB	Output is correct
58	Correct	3 ms	13868 KB	Output is correct
59	Correct	449 ms	31984 KB	Output is correct
60	Correct	563 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	436 ms	29908 KB	Output is correct
64	Correct	6 ms	13972 KB	Output is correct
65	Correct	26 ms	15248 KB	Output is correct
66	Correct	209 ms	27252 KB	Output is correct
67	Correct	616 ms	41752 KB	Output is correct
68	Correct	623 ms	42508 KB	Output is correct
69	Correct	9 ms	14472 KB	Output is correct
70	Correct	113 ms	21892 KB	Output is correct
71	Correct	396 ms	35588 KB	Output is correct
72	Correct	406 ms	35588 KB	Output is correct
73	Correct	133 ms	19092 KB	Output is correct
74	Correct	563 ms	31532 KB	Output is correct
75	Correct	29 ms	16200 KB	Output is correct
76	Correct	453 ms	34572 KB	Output is correct
77	Correct	359 ms	34572 KB	Output is correct
78	Correct	36 ms	16408 KB	Output is correct
79	Correct	553 ms	40008 KB	Output is correct
80	Correct	0 ms	13868 KB	Output is correct
81	Correct	86 ms	20764 KB	Output is correct
82	Correct	436 ms	33816 KB	Output is correct
83	Correct	406 ms	31532 KB	Output is correct
84	Correct	389 ms	31532 KB	Output is correct
85	Correct	416 ms	31532 KB	Output is correct
86	Correct	476 ms	33252 KB	Output is correct
87	Correct	556 ms	33252 KB	Output is correct

Submission #24944

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