답안 #79533 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
79533	2018-10-15T01:57:52 Z	Dat160601	Network (BOI15_net)	C++17	100 / 100	700 ms	43484 KB

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
int n,u,v,deg[500007],ans=0;
vector <int> edge[500007],sv;
void dfs(int u,int par){
	bool leaf=true;
	for(int v:edge[u]){
		if(v==par) continue;
		dfs(v,u);
		leaf=false;
	}
	if(leaf) ans++, sv.pb(u);
}
int main(){
	ios_base::sync_with_stdio(0);
	cin>>n;
	for(int i=1;i<n;i++){
		cin>>u>>v;
		deg[u]++, deg[v]++;
		edge[u].pb(v);
		edge[v].pb(u);
	}
	int root=-1;
	for(int i=1;i<=n;i++){
		if(deg[i]>=2){
			root=i;
			break;
		}
	}
	dfs(root,root);
	cout<<(ans+1)/2<<"\n";
	if(ans&1){
		int r=ans/2+1;
		for(int i=0;i<ans/2;i++){
			cout<<sv[i]<<" "<<sv[r]<<"\n";
			r++;
		}
		cout<<sv[ans/2]<<" "<<root<<"\n";
	}
	else{
		int r=ans/2;
		for(int i=0;i<ans/2;i++){
			cout<<sv[i]<<" "<<sv[r]<<"\n";
			r++;
		}
	}
}

Subtask #1
18.0 / 18.0

#	결과	실행 시간	메모리	Grader output
1	Correct	13 ms	12152 KB	Output is correct
2	Correct	12 ms	12272 KB	Output is correct
3	Correct	13 ms	12272 KB	Output is correct
4	Correct	12 ms	12272 KB	Output is correct
5	Correct	14 ms	12272 KB	Output is correct
6	Correct	12 ms	12292 KB	Output is correct
7	Correct	12 ms	12352 KB	Output is correct
8	Correct	12 ms	12368 KB	Output is correct
9	Correct	12 ms	12368 KB	Output is correct
10	Correct	13 ms	12368 KB	Output is correct
11	Correct	12 ms	12368 KB	Output is correct
12	Correct	12 ms	12368 KB	Output is correct
13	Correct	16 ms	12368 KB	Output is correct
14	Correct	12 ms	12368 KB	Output is correct
15	Correct	12 ms	12368 KB	Output is correct
16	Correct	12 ms	12368 KB	Output is correct
17	Correct	12 ms	12368 KB	Output is correct
18	Correct	12 ms	12368 KB	Output is correct
19	Correct	12 ms	12368 KB	Output is correct
20	Correct	15 ms	12368 KB	Output is correct

Subtask #2
45.0 / 45.0

#	결과	실행 시간	메모리	Grader output
1	Correct	13 ms	12152 KB	Output is correct
2	Correct	12 ms	12272 KB	Output is correct
3	Correct	13 ms	12272 KB	Output is correct
4	Correct	12 ms	12272 KB	Output is correct
5	Correct	14 ms	12272 KB	Output is correct
6	Correct	12 ms	12292 KB	Output is correct
7	Correct	12 ms	12352 KB	Output is correct
8	Correct	12 ms	12368 KB	Output is correct
9	Correct	12 ms	12368 KB	Output is correct
10	Correct	13 ms	12368 KB	Output is correct
11	Correct	12 ms	12368 KB	Output is correct
12	Correct	12 ms	12368 KB	Output is correct
13	Correct	16 ms	12368 KB	Output is correct
14	Correct	12 ms	12368 KB	Output is correct
15	Correct	12 ms	12368 KB	Output is correct
16	Correct	12 ms	12368 KB	Output is correct
17	Correct	12 ms	12368 KB	Output is correct
18	Correct	12 ms	12368 KB	Output is correct
19	Correct	12 ms	12368 KB	Output is correct
20	Correct	15 ms	12368 KB	Output is correct
21	Correct	12 ms	12368 KB	Output is correct
22	Correct	13 ms	12412 KB	Output is correct
23	Correct	13 ms	12412 KB	Output is correct
24	Correct	13 ms	12428 KB	Output is correct
25	Correct	13 ms	12444 KB	Output is correct
26	Correct	13 ms	12460 KB	Output is correct
27	Correct	13 ms	12460 KB	Output is correct
28	Correct	14 ms	12464 KB	Output is correct
29	Correct	13 ms	12464 KB	Output is correct
30	Correct	12 ms	12464 KB	Output is correct
31	Correct	13 ms	12476 KB	Output is correct
32	Correct	12 ms	12476 KB	Output is correct
33	Correct	12 ms	12476 KB	Output is correct
34	Correct	12 ms	12476 KB	Output is correct
35	Correct	12 ms	12476 KB	Output is correct
36	Correct	12 ms	12476 KB	Output is correct
37	Correct	12 ms	12476 KB	Output is correct
38	Correct	13 ms	12476 KB	Output is correct
39	Correct	16 ms	12476 KB	Output is correct
40	Correct	16 ms	12476 KB	Output is correct
41	Correct	12 ms	12476 KB	Output is correct
42	Correct	12 ms	12476 KB	Output is correct
43	Correct	13 ms	12476 KB	Output is correct
44	Correct	12 ms	12476 KB	Output is correct
45	Correct	12 ms	12496 KB	Output is correct
46	Correct	12 ms	12496 KB	Output is correct
47	Correct	12 ms	12496 KB	Output is correct
48	Correct	12 ms	12496 KB	Output is correct
49	Correct	13 ms	12500 KB	Output is correct
50	Correct	12 ms	12500 KB	Output is correct
51	Correct	12 ms	12500 KB	Output is correct
52	Correct	12 ms	12500 KB	Output is correct
53	Correct	12 ms	12500 KB	Output is correct
54	Correct	12 ms	12500 KB	Output is correct
55	Correct	12 ms	12500 KB	Output is correct
56	Correct	12 ms	12500 KB	Output is correct
57	Correct	13 ms	12500 KB	Output is correct
58	Correct	14 ms	12584 KB	Output is correct

Subtask #3
37.0 / 37.0

#	결과	실행 시간	메모리	Grader output
1	Correct	13 ms	12152 KB	Output is correct
2	Correct	12 ms	12272 KB	Output is correct
3	Correct	13 ms	12272 KB	Output is correct
4	Correct	12 ms	12272 KB	Output is correct
5	Correct	14 ms	12272 KB	Output is correct
6	Correct	12 ms	12292 KB	Output is correct
7	Correct	12 ms	12352 KB	Output is correct
8	Correct	12 ms	12368 KB	Output is correct
9	Correct	12 ms	12368 KB	Output is correct
10	Correct	13 ms	12368 KB	Output is correct
11	Correct	12 ms	12368 KB	Output is correct
12	Correct	12 ms	12368 KB	Output is correct
13	Correct	16 ms	12368 KB	Output is correct
14	Correct	12 ms	12368 KB	Output is correct
15	Correct	12 ms	12368 KB	Output is correct
16	Correct	12 ms	12368 KB	Output is correct
17	Correct	12 ms	12368 KB	Output is correct
18	Correct	12 ms	12368 KB	Output is correct
19	Correct	12 ms	12368 KB	Output is correct
20	Correct	15 ms	12368 KB	Output is correct
21	Correct	12 ms	12368 KB	Output is correct
22	Correct	13 ms	12412 KB	Output is correct
23	Correct	13 ms	12412 KB	Output is correct
24	Correct	13 ms	12428 KB	Output is correct
25	Correct	13 ms	12444 KB	Output is correct
26	Correct	13 ms	12460 KB	Output is correct
27	Correct	13 ms	12460 KB	Output is correct
28	Correct	14 ms	12464 KB	Output is correct
29	Correct	13 ms	12464 KB	Output is correct
30	Correct	12 ms	12464 KB	Output is correct
31	Correct	13 ms	12476 KB	Output is correct
32	Correct	12 ms	12476 KB	Output is correct
33	Correct	12 ms	12476 KB	Output is correct
34	Correct	12 ms	12476 KB	Output is correct
35	Correct	12 ms	12476 KB	Output is correct
36	Correct	12 ms	12476 KB	Output is correct
37	Correct	12 ms	12476 KB	Output is correct
38	Correct	13 ms	12476 KB	Output is correct
39	Correct	16 ms	12476 KB	Output is correct
40	Correct	16 ms	12476 KB	Output is correct
41	Correct	12 ms	12476 KB	Output is correct
42	Correct	12 ms	12476 KB	Output is correct
43	Correct	13 ms	12476 KB	Output is correct
44	Correct	12 ms	12476 KB	Output is correct
45	Correct	12 ms	12496 KB	Output is correct
46	Correct	12 ms	12496 KB	Output is correct
47	Correct	12 ms	12496 KB	Output is correct
48	Correct	12 ms	12496 KB	Output is correct
49	Correct	13 ms	12500 KB	Output is correct
50	Correct	12 ms	12500 KB	Output is correct
51	Correct	12 ms	12500 KB	Output is correct
52	Correct	12 ms	12500 KB	Output is correct
53	Correct	12 ms	12500 KB	Output is correct
54	Correct	12 ms	12500 KB	Output is correct
55	Correct	12 ms	12500 KB	Output is correct
56	Correct	12 ms	12500 KB	Output is correct
57	Correct	13 ms	12500 KB	Output is correct
58	Correct	14 ms	12584 KB	Output is correct
59	Correct	476 ms	32084 KB	Output is correct
60	Correct	623 ms	34452 KB	Output is correct
61	Correct	14 ms	34452 KB	Output is correct
62	Correct	13 ms	34452 KB	Output is correct
63	Correct	388 ms	34452 KB	Output is correct
64	Correct	15 ms	34452 KB	Output is correct
65	Correct	28 ms	34452 KB	Output is correct
66	Correct	198 ms	34452 KB	Output is correct
67	Correct	675 ms	42684 KB	Output is correct
68	Correct	670 ms	43484 KB	Output is correct
69	Correct	19 ms	43484 KB	Output is correct
70	Correct	129 ms	43484 KB	Output is correct
71	Correct	396 ms	43484 KB	Output is correct
72	Correct	454 ms	43484 KB	Output is correct
73	Correct	128 ms	43484 KB	Output is correct
74	Correct	640 ms	43484 KB	Output is correct
75	Correct	43 ms	43484 KB	Output is correct
76	Correct	410 ms	43484 KB	Output is correct
77	Correct	401 ms	43484 KB	Output is correct
78	Correct	46 ms	43484 KB	Output is correct
79	Correct	700 ms	43484 KB	Output is correct
80	Correct	14 ms	43484 KB	Output is correct
81	Correct	141 ms	43484 KB	Output is correct
82	Correct	514 ms	43484 KB	Output is correct
83	Correct	583 ms	43484 KB	Output is correct
84	Correct	591 ms	43484 KB	Output is correct
85	Correct	566 ms	43484 KB	Output is correct
86	Correct	544 ms	43484 KB	Output is correct
87	Correct	574 ms	43484 KB	Output is correct

답안 #79533

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