Submission #606815

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
606815	2022-07-26T08:41:37 Z	ThMinh_	Network (BOI15_net)	C++14	100 / 100	672 ms	239644 KB

#include<bits/stdc++.h>
#define forin(i,a,b) for(int i=a;i<=b;++i)
#define forv(a,b) for(auto &a:b)
#define ii pair<int, int>
using namespace std;
const int N = 5e5+10;
int n, root;
int color[N];
vector<int> adj[N];
vector<ii> ans;
queue<int> dfs(int u) {
	color[u] = 1;
	queue<int> res;
	if(adj[u].size() == 1) {res.push(u); return res;}
	forv(v, adj[u]) if(!color[v]) {
		queue<int> q = dfs(v);
		if(res.size() + q.size() > 2 && res.size() > 0 && q.size() > 0) {
			ans.push_back({res.front(), q.front()});
			res.pop(); q.pop();
		}
		while(!q.empty()) {res.push(q.front()); q.pop();}
	}
	return res;
}
int main () {
	cin.tie(0)->sync_with_stdio(0);
	if(fopen("Task.inp","r")) {
		freopen("Task.inp","r",stdin);
		freopen("WA.out","w",stdout);
	}
	cin>>n;
	forin(i,1,n - 1) {
		int u, v; cin>>u>>v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	queue<int> slt;
	forin(i,1,n) if(adj[i].size() > 1) {slt = dfs(i); root = i; break;}
	if(slt.size() == 2) {root = slt.front(); slt.pop();}
	if(slt.size() == 1) ans.push_back({root, slt.front()});
	cout<<ans.size()<<"\n";
	forv(v, ans) cout<<v.first<<" "<<v.second<<"\n";
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:28:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |   freopen("Task.inp","r",stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
net.cpp:29:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |   freopen("WA.out","w",stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	8 ms	11996 KB	Output is correct
2	Correct	7 ms	12068 KB	Output is correct
3	Correct	6 ms	12052 KB	Output is correct
4	Correct	8 ms	11988 KB	Output is correct
5	Correct	9 ms	12032 KB	Output is correct
6	Correct	6 ms	12044 KB	Output is correct
7	Correct	6 ms	12008 KB	Output is correct
8	Correct	8 ms	11988 KB	Output is correct
9	Correct	8 ms	11988 KB	Output is correct
10	Correct	9 ms	11972 KB	Output is correct
11	Correct	11 ms	11988 KB	Output is correct
12	Correct	6 ms	11988 KB	Output is correct
13	Correct	7 ms	11988 KB	Output is correct
14	Correct	6 ms	11988 KB	Output is correct
15	Correct	5 ms	11988 KB	Output is correct
16	Correct	6 ms	12036 KB	Output is correct
17	Correct	7 ms	11988 KB	Output is correct
18	Correct	6 ms	11952 KB	Output is correct
19	Correct	6 ms	11988 KB	Output is correct
20	Correct	11 ms	11992 KB	Output is correct

Subtask #2
45.0 / 45.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	8 ms	11996 KB	Output is correct
2	Correct	7 ms	12068 KB	Output is correct
3	Correct	6 ms	12052 KB	Output is correct
4	Correct	8 ms	11988 KB	Output is correct
5	Correct	9 ms	12032 KB	Output is correct
6	Correct	6 ms	12044 KB	Output is correct
7	Correct	6 ms	12008 KB	Output is correct
8	Correct	8 ms	11988 KB	Output is correct
9	Correct	8 ms	11988 KB	Output is correct
10	Correct	9 ms	11972 KB	Output is correct
11	Correct	11 ms	11988 KB	Output is correct
12	Correct	6 ms	11988 KB	Output is correct
13	Correct	7 ms	11988 KB	Output is correct
14	Correct	6 ms	11988 KB	Output is correct
15	Correct	5 ms	11988 KB	Output is correct
16	Correct	6 ms	12036 KB	Output is correct
17	Correct	7 ms	11988 KB	Output is correct
18	Correct	6 ms	11952 KB	Output is correct
19	Correct	6 ms	11988 KB	Output is correct
20	Correct	11 ms	11992 KB	Output is correct
21	Correct	6 ms	11972 KB	Output is correct
22	Correct	9 ms	12116 KB	Output is correct
23	Correct	9 ms	12180 KB	Output is correct
24	Correct	7 ms	12116 KB	Output is correct
25	Correct	7 ms	12096 KB	Output is correct
26	Correct	10 ms	12116 KB	Output is correct
27	Correct	9 ms	12116 KB	Output is correct
28	Correct	9 ms	12152 KB	Output is correct
29	Correct	8 ms	12116 KB	Output is correct
30	Correct	17 ms	12012 KB	Output is correct
31	Correct	7 ms	12116 KB	Output is correct
32	Correct	6 ms	11988 KB	Output is correct
33	Correct	8 ms	11988 KB	Output is correct
34	Correct	9 ms	12048 KB	Output is correct
35	Correct	8 ms	11988 KB	Output is correct
36	Correct	7 ms	11988 KB	Output is correct
37	Correct	9 ms	12372 KB	Output is correct
38	Correct	9 ms	12660 KB	Output is correct
39	Correct	7 ms	12060 KB	Output is correct
40	Correct	9 ms	11988 KB	Output is correct
41	Correct	9 ms	11988 KB	Output is correct
42	Correct	10 ms	12060 KB	Output is correct
43	Correct	8 ms	12116 KB	Output is correct
44	Correct	8 ms	11988 KB	Output is correct
45	Correct	7 ms	11980 KB	Output is correct
46	Correct	7 ms	12072 KB	Output is correct
47	Correct	8 ms	11988 KB	Output is correct
48	Correct	9 ms	11988 KB	Output is correct
49	Correct	7 ms	12000 KB	Output is correct
50	Correct	8 ms	11988 KB	Output is correct
51	Correct	6 ms	11988 KB	Output is correct
52	Correct	6 ms	12116 KB	Output is correct
53	Correct	7 ms	12244 KB	Output is correct
54	Correct	6 ms	12004 KB	Output is correct
55	Correct	8 ms	12020 KB	Output is correct
56	Correct	6 ms	11988 KB	Output is correct
57	Correct	8 ms	11988 KB	Output is correct
58	Correct	7 ms	12080 KB	Output is correct

Subtask #3
37.0 / 37.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	8 ms	11996 KB	Output is correct
2	Correct	7 ms	12068 KB	Output is correct
3	Correct	6 ms	12052 KB	Output is correct
4	Correct	8 ms	11988 KB	Output is correct
5	Correct	9 ms	12032 KB	Output is correct
6	Correct	6 ms	12044 KB	Output is correct
7	Correct	6 ms	12008 KB	Output is correct
8	Correct	8 ms	11988 KB	Output is correct
9	Correct	8 ms	11988 KB	Output is correct
10	Correct	9 ms	11972 KB	Output is correct
11	Correct	11 ms	11988 KB	Output is correct
12	Correct	6 ms	11988 KB	Output is correct
13	Correct	7 ms	11988 KB	Output is correct
14	Correct	6 ms	11988 KB	Output is correct
15	Correct	5 ms	11988 KB	Output is correct
16	Correct	6 ms	12036 KB	Output is correct
17	Correct	7 ms	11988 KB	Output is correct
18	Correct	6 ms	11952 KB	Output is correct
19	Correct	6 ms	11988 KB	Output is correct
20	Correct	11 ms	11992 KB	Output is correct
21	Correct	6 ms	11972 KB	Output is correct
22	Correct	9 ms	12116 KB	Output is correct
23	Correct	9 ms	12180 KB	Output is correct
24	Correct	7 ms	12116 KB	Output is correct
25	Correct	7 ms	12096 KB	Output is correct
26	Correct	10 ms	12116 KB	Output is correct
27	Correct	9 ms	12116 KB	Output is correct
28	Correct	9 ms	12152 KB	Output is correct
29	Correct	8 ms	12116 KB	Output is correct
30	Correct	17 ms	12012 KB	Output is correct
31	Correct	7 ms	12116 KB	Output is correct
32	Correct	6 ms	11988 KB	Output is correct
33	Correct	8 ms	11988 KB	Output is correct
34	Correct	9 ms	12048 KB	Output is correct
35	Correct	8 ms	11988 KB	Output is correct
36	Correct	7 ms	11988 KB	Output is correct
37	Correct	9 ms	12372 KB	Output is correct
38	Correct	9 ms	12660 KB	Output is correct
39	Correct	7 ms	12060 KB	Output is correct
40	Correct	9 ms	11988 KB	Output is correct
41	Correct	9 ms	11988 KB	Output is correct
42	Correct	10 ms	12060 KB	Output is correct
43	Correct	8 ms	12116 KB	Output is correct
44	Correct	8 ms	11988 KB	Output is correct
45	Correct	7 ms	11980 KB	Output is correct
46	Correct	7 ms	12072 KB	Output is correct
47	Correct	8 ms	11988 KB	Output is correct
48	Correct	9 ms	11988 KB	Output is correct
49	Correct	7 ms	12000 KB	Output is correct
50	Correct	8 ms	11988 KB	Output is correct
51	Correct	6 ms	11988 KB	Output is correct
52	Correct	6 ms	12116 KB	Output is correct
53	Correct	7 ms	12244 KB	Output is correct
54	Correct	6 ms	12004 KB	Output is correct
55	Correct	8 ms	12020 KB	Output is correct
56	Correct	6 ms	11988 KB	Output is correct
57	Correct	8 ms	11988 KB	Output is correct
58	Correct	7 ms	12080 KB	Output is correct
59	Correct	347 ms	31728 KB	Output is correct
60	Correct	486 ms	34080 KB	Output is correct
61	Correct	8 ms	11988 KB	Output is correct
62	Correct	8 ms	11988 KB	Output is correct
63	Correct	374 ms	29804 KB	Output is correct
64	Correct	10 ms	16084 KB	Output is correct
65	Correct	22 ms	26788 KB	Output is correct
66	Correct	202 ms	148684 KB	Output is correct
67	Correct	622 ms	235472 KB	Output is correct
68	Correct	672 ms	239644 KB	Output is correct
69	Correct	16 ms	12884 KB	Output is correct
70	Correct	129 ms	20040 KB	Output is correct
71	Correct	306 ms	37372 KB	Output is correct
72	Correct	326 ms	36536 KB	Output is correct
73	Correct	128 ms	18148 KB	Output is correct
74	Correct	499 ms	33332 KB	Output is correct
75	Correct	32 ms	14956 KB	Output is correct
76	Correct	355 ms	37060 KB	Output is correct
77	Correct	389 ms	37316 KB	Output is correct
78	Correct	49 ms	29688 KB	Output is correct
79	Correct	663 ms	206976 KB	Output is correct
80	Correct	9 ms	12220 KB	Output is correct
81	Correct	129 ms	20080 KB	Output is correct
82	Correct	482 ms	35280 KB	Output is correct
83	Correct	522 ms	33384 KB	Output is correct
84	Correct	534 ms	33260 KB	Output is correct
85	Correct	431 ms	33208 KB	Output is correct
86	Correct	456 ms	34340 KB	Output is correct
87	Correct	494 ms	34380 KB	Output is correct

Submission #606815

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