Submission #125052

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
125052	2019-07-04T13:57:01 Z	wilwxk	Network (BOI15_net)	C++14	100 / 100	649 ms	77324 KB

#include <bits/stdc++.h>
using namespace std;

const int MAXN=5e5+5;
vector<int> g[MAXN];
int leave[MAXN][2];
vector<pair<int, int> > respf; 
int n, raiz;

void dfs(int cur, int p) {
	if(g[cur].size()==1) leave[cur][0]=cur;
	if(g[cur].size()==1) return;
	for(auto viz : g[cur]) {
		if(viz==p) continue;
		dfs(viz, cur);
		if(!leave[cur][0]) {
			leave[cur][0]=leave[viz][0];
			leave[cur][1]=leave[viz][1];
			continue;
		}
		if(leave[cur][1]) {
			respf.push_back({leave[cur][1], leave[viz][0]});
			leave[cur][1]=leave[viz][1];
		}
		else {
			swap(leave[cur][0], leave[viz][0]);
			if(leave[viz][1]) respf.push_back({leave[viz][0], leave[viz][1]});
			else leave[cur][1]=leave[viz][0];
		}
	}
	// printf("%d >> %d %d\n", cur, leave[cur][0], leave[cur][1]);
}

int main() {
	scanf("%d", &n);
	for(int i=1; i<=n-1; i++) {
		int a, b; scanf("%d %d", &a, &b);
		g[a].push_back(b); g[b].push_back(a);
	}

	for(int i=1; i<=n; i++) if(g[i].size()!=1) raiz=i;
	dfs(raiz, raiz);
	if(!leave[raiz][1]) leave[raiz][1]=raiz;
	respf.push_back({leave[raiz][0], leave[raiz][1]});

	printf("%d\n", respf.size());
	for(auto cara : respf) printf("%d %d\n", cara.first, cara.second);
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:46:29: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<std::pair<int, int> >::size_type {aka long unsigned int}' [-Wformat=]
  printf("%d\n", respf.size());
                 ~~~~~~~~~~~~^
net.cpp:35:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
net.cpp:37:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int a, b; scanf("%d %d", &a, &b);
             ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	12 ms	12024 KB	Output is correct
2	Correct	16 ms	12024 KB	Output is correct
3	Correct	14 ms	12152 KB	Output is correct
4	Correct	23 ms	12068 KB	Output is correct
5	Correct	13 ms	12024 KB	Output is correct
6	Correct	12 ms	12024 KB	Output is correct
7	Correct	13 ms	12116 KB	Output is correct
8	Correct	12 ms	12024 KB	Output is correct
9	Correct	12 ms	12024 KB	Output is correct
10	Correct	12 ms	12024 KB	Output is correct
11	Correct	12 ms	12024 KB	Output is correct
12	Correct	12 ms	12024 KB	Output is correct
13	Correct	12 ms	12024 KB	Output is correct
14	Correct	15 ms	12024 KB	Output is correct
15	Correct	13 ms	12028 KB	Output is correct
16	Correct	12 ms	12024 KB	Output is correct
17	Correct	12 ms	12084 KB	Output is correct
18	Correct	12 ms	12024 KB	Output is correct
19	Correct	12 ms	12024 KB	Output is correct
20	Correct	12 ms	12024 KB	Output is correct

Subtask #2
45.0 / 45.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	12 ms	12024 KB	Output is correct
2	Correct	16 ms	12024 KB	Output is correct
3	Correct	14 ms	12152 KB	Output is correct
4	Correct	23 ms	12068 KB	Output is correct
5	Correct	13 ms	12024 KB	Output is correct
6	Correct	12 ms	12024 KB	Output is correct
7	Correct	13 ms	12116 KB	Output is correct
8	Correct	12 ms	12024 KB	Output is correct
9	Correct	12 ms	12024 KB	Output is correct
10	Correct	12 ms	12024 KB	Output is correct
11	Correct	12 ms	12024 KB	Output is correct
12	Correct	12 ms	12024 KB	Output is correct
13	Correct	12 ms	12024 KB	Output is correct
14	Correct	15 ms	12024 KB	Output is correct
15	Correct	13 ms	12028 KB	Output is correct
16	Correct	12 ms	12024 KB	Output is correct
17	Correct	12 ms	12084 KB	Output is correct
18	Correct	12 ms	12024 KB	Output is correct
19	Correct	12 ms	12024 KB	Output is correct
20	Correct	12 ms	12024 KB	Output is correct
21	Correct	12 ms	12024 KB	Output is correct
22	Correct	13 ms	12152 KB	Output is correct
23	Correct	13 ms	12168 KB	Output is correct
24	Correct	13 ms	12152 KB	Output is correct
25	Correct	13 ms	12152 KB	Output is correct
26	Correct	13 ms	12024 KB	Output is correct
27	Correct	13 ms	12152 KB	Output is correct
28	Correct	13 ms	12152 KB	Output is correct
29	Correct	13 ms	12152 KB	Output is correct
30	Correct	13 ms	12004 KB	Output is correct
31	Correct	13 ms	12152 KB	Output is correct
32	Correct	13 ms	12024 KB	Output is correct
33	Correct	12 ms	12024 KB	Output is correct
34	Correct	12 ms	12024 KB	Output is correct
35	Correct	12 ms	12052 KB	Output is correct
36	Correct	12 ms	12024 KB	Output is correct
37	Correct	12 ms	12152 KB	Output is correct
38	Correct	13 ms	12108 KB	Output is correct
39	Correct	12 ms	11996 KB	Output is correct
40	Correct	13 ms	12124 KB	Output is correct
41	Correct	12 ms	12068 KB	Output is correct
42	Correct	13 ms	12024 KB	Output is correct
43	Correct	12 ms	12152 KB	Output is correct
44	Correct	12 ms	12024 KB	Output is correct
45	Correct	12 ms	12024 KB	Output is correct
46	Correct	13 ms	12152 KB	Output is correct
47	Correct	12 ms	12024 KB	Output is correct
48	Correct	12 ms	12024 KB	Output is correct
49	Correct	12 ms	12148 KB	Output is correct
50	Correct	12 ms	12024 KB	Output is correct
51	Correct	12 ms	12048 KB	Output is correct
52	Correct	12 ms	12152 KB	Output is correct
53	Correct	13 ms	12152 KB	Output is correct
54	Correct	12 ms	12024 KB	Output is correct
55	Correct	13 ms	12124 KB	Output is correct
56	Correct	14 ms	12024 KB	Output is correct
57	Correct	13 ms	12116 KB	Output is correct
58	Correct	16 ms	12208 KB	Output is correct

Subtask #3
37.0 / 37.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	12 ms	12024 KB	Output is correct
2	Correct	16 ms	12024 KB	Output is correct
3	Correct	14 ms	12152 KB	Output is correct
4	Correct	23 ms	12068 KB	Output is correct
5	Correct	13 ms	12024 KB	Output is correct
6	Correct	12 ms	12024 KB	Output is correct
7	Correct	13 ms	12116 KB	Output is correct
8	Correct	12 ms	12024 KB	Output is correct
9	Correct	12 ms	12024 KB	Output is correct
10	Correct	12 ms	12024 KB	Output is correct
11	Correct	12 ms	12024 KB	Output is correct
12	Correct	12 ms	12024 KB	Output is correct
13	Correct	12 ms	12024 KB	Output is correct
14	Correct	15 ms	12024 KB	Output is correct
15	Correct	13 ms	12028 KB	Output is correct
16	Correct	12 ms	12024 KB	Output is correct
17	Correct	12 ms	12084 KB	Output is correct
18	Correct	12 ms	12024 KB	Output is correct
19	Correct	12 ms	12024 KB	Output is correct
20	Correct	12 ms	12024 KB	Output is correct
21	Correct	12 ms	12024 KB	Output is correct
22	Correct	13 ms	12152 KB	Output is correct
23	Correct	13 ms	12168 KB	Output is correct
24	Correct	13 ms	12152 KB	Output is correct
25	Correct	13 ms	12152 KB	Output is correct
26	Correct	13 ms	12024 KB	Output is correct
27	Correct	13 ms	12152 KB	Output is correct
28	Correct	13 ms	12152 KB	Output is correct
29	Correct	13 ms	12152 KB	Output is correct
30	Correct	13 ms	12004 KB	Output is correct
31	Correct	13 ms	12152 KB	Output is correct
32	Correct	13 ms	12024 KB	Output is correct
33	Correct	12 ms	12024 KB	Output is correct
34	Correct	12 ms	12024 KB	Output is correct
35	Correct	12 ms	12052 KB	Output is correct
36	Correct	12 ms	12024 KB	Output is correct
37	Correct	12 ms	12152 KB	Output is correct
38	Correct	13 ms	12108 KB	Output is correct
39	Correct	12 ms	11996 KB	Output is correct
40	Correct	13 ms	12124 KB	Output is correct
41	Correct	12 ms	12068 KB	Output is correct
42	Correct	13 ms	12024 KB	Output is correct
43	Correct	12 ms	12152 KB	Output is correct
44	Correct	12 ms	12024 KB	Output is correct
45	Correct	12 ms	12024 KB	Output is correct
46	Correct	13 ms	12152 KB	Output is correct
47	Correct	12 ms	12024 KB	Output is correct
48	Correct	12 ms	12024 KB	Output is correct
49	Correct	12 ms	12148 KB	Output is correct
50	Correct	12 ms	12024 KB	Output is correct
51	Correct	12 ms	12048 KB	Output is correct
52	Correct	12 ms	12152 KB	Output is correct
53	Correct	13 ms	12152 KB	Output is correct
54	Correct	12 ms	12024 KB	Output is correct
55	Correct	13 ms	12124 KB	Output is correct
56	Correct	14 ms	12024 KB	Output is correct
57	Correct	13 ms	12116 KB	Output is correct
58	Correct	16 ms	12208 KB	Output is correct
59	Correct	417 ms	39612 KB	Output is correct
60	Correct	523 ms	42672 KB	Output is correct
61	Correct	12 ms	12000 KB	Output is correct
62	Correct	13 ms	12024 KB	Output is correct
63	Correct	370 ms	36776 KB	Output is correct
64	Correct	15 ms	12536 KB	Output is correct
65	Correct	28 ms	14396 KB	Output is correct
66	Correct	191 ms	30112 KB	Output is correct
67	Correct	602 ms	77324 KB	Output is correct
68	Correct	588 ms	65076 KB	Output is correct
69	Correct	20 ms	13048 KB	Output is correct
70	Correct	117 ms	22532 KB	Output is correct
71	Correct	353 ms	45828 KB	Output is correct
72	Correct	373 ms	44576 KB	Output is correct
73	Correct	127 ms	20192 KB	Output is correct
74	Correct	552 ms	41576 KB	Output is correct
75	Correct	43 ms	15736 KB	Output is correct
76	Correct	364 ms	45524 KB	Output is correct
77	Correct	401 ms	45624 KB	Output is correct
78	Correct	49 ms	16376 KB	Output is correct
79	Correct	609 ms	56180 KB	Output is correct
80	Correct	14 ms	12280 KB	Output is correct
81	Correct	133 ms	22636 KB	Output is correct
82	Correct	436 ms	43448 KB	Output is correct
83	Correct	527 ms	41604 KB	Output is correct
84	Correct	649 ms	41664 KB	Output is correct
85	Correct	530 ms	41584 KB	Output is correct
86	Correct	504 ms	42712 KB	Output is correct
87	Correct	520 ms	42724 KB	Output is correct

Submission #125052

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