Submission #69459

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
69459	2018-08-21T01:12:49 Z	kingpig9	Network (BOI15_net)	C++11	100 / 100	698 ms	154532 KB

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<int, int> pii;

#define debug(...) fprintf(stderr, __VA_ARGS__)
//#define debug(...)
#define all(v) (v).begin(), (v).end()
#define fillchar(a, s) memset((a), (s), sizeof(a))
#define fi first
#define se second

int N;
vector<int> adj[500010];
vector<int> leaves;

void dfs (int x, int p) {
	if (adj[x].size() == 1) {
		leaves.push_back(x);
	}
	for (int y : adj[x]) {
		if (y != p) {
			dfs(y, x);
		}
	}
}

int main() {
	scanf("%d", &N);
	for (int i = 1; i < N; i++) {
		int x, y;
		scanf("%d %d", &x, &y);
		adj[x].push_back(y);
		adj[y].push_back(x);
	}

	int root = 1;
	while (adj[root].size() == 1) {
		root++;
	}
	dfs(root, -1);

	vector<pii> ans;

	for (int i = 0, j = leaves.size() / 2; j < leaves.size(); i++, j++) {
		ans.push_back({leaves[i], leaves[j]});
	}

	printf("%lu\n", ans.size());
	for (pii p : ans) {
		printf("%d %d\n", p.fi, p.se);
	}
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:46:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0, j = leaves.size() / 2; j < leaves.size(); i++, j++) {
                                         ~~^~~~~~~~~~~~~~~
net.cpp:30:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
  ~~~~~^~~~~~~~~~
net.cpp:33:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &x, &y);
   ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	10 ms	11988 KB	Output is correct
2	Correct	15 ms	12132 KB	Output is correct
3	Correct	11 ms	12192 KB	Output is correct
4	Correct	12 ms	12192 KB	Output is correct
5	Correct	12 ms	12192 KB	Output is correct
6	Correct	12 ms	12284 KB	Output is correct
7	Correct	12 ms	12396 KB	Output is correct
8	Correct	12 ms	12464 KB	Output is correct
9	Correct	12 ms	12464 KB	Output is correct
10	Correct	13 ms	12464 KB	Output is correct
11	Correct	15 ms	12464 KB	Output is correct
12	Correct	12 ms	12464 KB	Output is correct
13	Correct	12 ms	12464 KB	Output is correct
14	Correct	13 ms	12464 KB	Output is correct
15	Correct	12 ms	12464 KB	Output is correct
16	Correct	13 ms	12464 KB	Output is correct
17	Correct	13 ms	12464 KB	Output is correct
18	Correct	14 ms	12464 KB	Output is correct
19	Correct	12 ms	12464 KB	Output is correct
20	Correct	13 ms	12464 KB	Output is correct

Subtask #2
45.0 / 45.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	10 ms	11988 KB	Output is correct
2	Correct	15 ms	12132 KB	Output is correct
3	Correct	11 ms	12192 KB	Output is correct
4	Correct	12 ms	12192 KB	Output is correct
5	Correct	12 ms	12192 KB	Output is correct
6	Correct	12 ms	12284 KB	Output is correct
7	Correct	12 ms	12396 KB	Output is correct
8	Correct	12 ms	12464 KB	Output is correct
9	Correct	12 ms	12464 KB	Output is correct
10	Correct	13 ms	12464 KB	Output is correct
11	Correct	15 ms	12464 KB	Output is correct
12	Correct	12 ms	12464 KB	Output is correct
13	Correct	12 ms	12464 KB	Output is correct
14	Correct	13 ms	12464 KB	Output is correct
15	Correct	12 ms	12464 KB	Output is correct
16	Correct	13 ms	12464 KB	Output is correct
17	Correct	13 ms	12464 KB	Output is correct
18	Correct	14 ms	12464 KB	Output is correct
19	Correct	12 ms	12464 KB	Output is correct
20	Correct	13 ms	12464 KB	Output is correct
21	Correct	15 ms	12464 KB	Output is correct
22	Correct	16 ms	12568 KB	Output is correct
23	Correct	14 ms	12604 KB	Output is correct
24	Correct	15 ms	12640 KB	Output is correct
25	Correct	15 ms	12788 KB	Output is correct
26	Correct	15 ms	12788 KB	Output is correct
27	Correct	16 ms	12788 KB	Output is correct
28	Correct	14 ms	12852 KB	Output is correct
29	Correct	19 ms	12852 KB	Output is correct
30	Correct	12 ms	12852 KB	Output is correct
31	Correct	17 ms	12852 KB	Output is correct
32	Correct	16 ms	12852 KB	Output is correct
33	Correct	14 ms	12852 KB	Output is correct
34	Correct	13 ms	12852 KB	Output is correct
35	Correct	14 ms	12852 KB	Output is correct
36	Correct	13 ms	12852 KB	Output is correct
37	Correct	12 ms	12852 KB	Output is correct
38	Correct	16 ms	12852 KB	Output is correct
39	Correct	13 ms	12852 KB	Output is correct
40	Correct	12 ms	12852 KB	Output is correct
41	Correct	13 ms	12852 KB	Output is correct
42	Correct	13 ms	12852 KB	Output is correct
43	Correct	11 ms	12852 KB	Output is correct
44	Correct	12 ms	12852 KB	Output is correct
45	Correct	12 ms	12852 KB	Output is correct
46	Correct	14 ms	12852 KB	Output is correct
47	Correct	11 ms	12852 KB	Output is correct
48	Correct	12 ms	12852 KB	Output is correct
49	Correct	12 ms	12884 KB	Output is correct
50	Correct	11 ms	12884 KB	Output is correct
51	Correct	13 ms	12884 KB	Output is correct
52	Correct	13 ms	12884 KB	Output is correct
53	Correct	13 ms	12912 KB	Output is correct
54	Correct	11 ms	12912 KB	Output is correct
55	Correct	12 ms	12912 KB	Output is correct
56	Correct	12 ms	12912 KB	Output is correct
57	Correct	13 ms	12912 KB	Output is correct
58	Correct	17 ms	12936 KB	Output is correct

Subtask #3
37.0 / 37.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	10 ms	11988 KB	Output is correct
2	Correct	15 ms	12132 KB	Output is correct
3	Correct	11 ms	12192 KB	Output is correct
4	Correct	12 ms	12192 KB	Output is correct
5	Correct	12 ms	12192 KB	Output is correct
6	Correct	12 ms	12284 KB	Output is correct
7	Correct	12 ms	12396 KB	Output is correct
8	Correct	12 ms	12464 KB	Output is correct
9	Correct	12 ms	12464 KB	Output is correct
10	Correct	13 ms	12464 KB	Output is correct
11	Correct	15 ms	12464 KB	Output is correct
12	Correct	12 ms	12464 KB	Output is correct
13	Correct	12 ms	12464 KB	Output is correct
14	Correct	13 ms	12464 KB	Output is correct
15	Correct	12 ms	12464 KB	Output is correct
16	Correct	13 ms	12464 KB	Output is correct
17	Correct	13 ms	12464 KB	Output is correct
18	Correct	14 ms	12464 KB	Output is correct
19	Correct	12 ms	12464 KB	Output is correct
20	Correct	13 ms	12464 KB	Output is correct
21	Correct	15 ms	12464 KB	Output is correct
22	Correct	16 ms	12568 KB	Output is correct
23	Correct	14 ms	12604 KB	Output is correct
24	Correct	15 ms	12640 KB	Output is correct
25	Correct	15 ms	12788 KB	Output is correct
26	Correct	15 ms	12788 KB	Output is correct
27	Correct	16 ms	12788 KB	Output is correct
28	Correct	14 ms	12852 KB	Output is correct
29	Correct	19 ms	12852 KB	Output is correct
30	Correct	12 ms	12852 KB	Output is correct
31	Correct	17 ms	12852 KB	Output is correct
32	Correct	16 ms	12852 KB	Output is correct
33	Correct	14 ms	12852 KB	Output is correct
34	Correct	13 ms	12852 KB	Output is correct
35	Correct	14 ms	12852 KB	Output is correct
36	Correct	13 ms	12852 KB	Output is correct
37	Correct	12 ms	12852 KB	Output is correct
38	Correct	16 ms	12852 KB	Output is correct
39	Correct	13 ms	12852 KB	Output is correct
40	Correct	12 ms	12852 KB	Output is correct
41	Correct	13 ms	12852 KB	Output is correct
42	Correct	13 ms	12852 KB	Output is correct
43	Correct	11 ms	12852 KB	Output is correct
44	Correct	12 ms	12852 KB	Output is correct
45	Correct	12 ms	12852 KB	Output is correct
46	Correct	14 ms	12852 KB	Output is correct
47	Correct	11 ms	12852 KB	Output is correct
48	Correct	12 ms	12852 KB	Output is correct
49	Correct	12 ms	12884 KB	Output is correct
50	Correct	11 ms	12884 KB	Output is correct
51	Correct	13 ms	12884 KB	Output is correct
52	Correct	13 ms	12884 KB	Output is correct
53	Correct	13 ms	12912 KB	Output is correct
54	Correct	11 ms	12912 KB	Output is correct
55	Correct	12 ms	12912 KB	Output is correct
56	Correct	12 ms	12912 KB	Output is correct
57	Correct	13 ms	12912 KB	Output is correct
58	Correct	17 ms	12936 KB	Output is correct
59	Correct	452 ms	38012 KB	Output is correct
60	Correct	551 ms	46824 KB	Output is correct
61	Correct	12 ms	46824 KB	Output is correct
62	Correct	12 ms	46824 KB	Output is correct
63	Correct	393 ms	48216 KB	Output is correct
64	Correct	19 ms	48216 KB	Output is correct
65	Correct	29 ms	48216 KB	Output is correct
66	Correct	192 ms	48216 KB	Output is correct
67	Correct	616 ms	68216 KB	Output is correct
68	Correct	627 ms	76032 KB	Output is correct
69	Correct	29 ms	76032 KB	Output is correct
70	Correct	142 ms	76032 KB	Output is correct
71	Correct	450 ms	80604 KB	Output is correct
72	Correct	468 ms	85904 KB	Output is correct
73	Correct	165 ms	85904 KB	Output is correct
74	Correct	589 ms	90260 KB	Output is correct
75	Correct	47 ms	90260 KB	Output is correct
76	Correct	413 ms	102128 KB	Output is correct
77	Correct	463 ms	109140 KB	Output is correct
78	Correct	60 ms	109140 KB	Output is correct
79	Correct	698 ms	118048 KB	Output is correct
80	Correct	14 ms	118048 KB	Output is correct
81	Correct	155 ms	118048 KB	Output is correct
82	Correct	538 ms	122476 KB	Output is correct
83	Correct	596 ms	126632 KB	Output is correct
84	Correct	661 ms	133220 KB	Output is correct
85	Correct	635 ms	139968 KB	Output is correct
86	Correct	607 ms	147800 KB	Output is correct
87	Correct	622 ms	154532 KB	Output is correct

Submission #69459

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