Submission #22983

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
22983	2017-05-01T02:34:20 Z	model_code	Network (BOI15_net)	C++11	100 / 100	873 ms	63228 KB

/*/
  Task: net
  Model solution
  Author: Bartosz Kostka 
/*/

#include "bits/stdc++.h"

using namespace std;

const int MAXN = 500007;

bool odw[MAXN];
int leaves[MAXN];
int numleaves;

vector <int> G[MAXN], S[MAXN];

void dfs(int v)
{
  odw[v] = true;
  if((int)G[v].size() == 1)
    leaves[v] = 1;
  for(auto w : G[v])
    if(odw[w]==false)
    {
      dfs(w);
      leaves[v] += leaves[w];
    }
} 

int findcut(int v)
{
  odw[v] = true;
  for(auto w : G[v])
    if(odw[w] == false)
      if(leaves[w] > numleaves/2)
        return findcut(w);
  return v;
}

void newdfs(int v, int tree)
{
  //cerr << v << " " << tree << "T\n";
  odw[v] = true;
  if((int)G[v].size() == 1)
    S[tree].push_back(v);
  for(auto w : G[v])
    if(odw[w] == false)
      newdfs(w,tree);
}

int subtree;

int cut(int n)
{
  dfs(1);
  for(int i=1; i<=n; i++)
    odw[i] = false;
  int w = findcut(1);
  for(int i=1; i<=n; i++)
    odw[i] = false;
  odw[w] = true;
  for(auto v : G[w])
    newdfs(v,++subtree);
  return w;
}

vector <int> W;

int next(int e, int nn)
{
  e += 2;
  if(e==nn)
    e = 1;
  return e;
}

int main()
{
  int n;
  scanf("%d", &n);
  if(n==1)
  {
    printf("0\n");
    return 0;
  }
  if(n==2)
  {
    printf("1\n1 2\n");
    return 0;
  }
  for(int i=1; i<n; 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((int)G[i].size() == 1)
      numleaves++;
  int res = (numleaves+1)/2;
  printf("%d\n", res);
  int w = cut(n);
  
  W.resize(2*res);
  int e = 0;
  for(int i=1; i<=subtree; i++)
  {
    for(auto ele : S[i])
    {
      W[e] = ele;
      e = next(e,2*res);
      //cerr << ele << "." << e << "\n";
    }
  } 

  if((!W.empty()) and W.back() == 0)
    W.back() = w;

  for(int i=0; i<(int)W.size(); i+=2)
    printf("%d %d\n", W[i], W[i+1]);
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:82:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &n);
                  ^
net.cpp:96:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &a, &b);
                          ^

Subtask #1
18.0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	3 ms	27904 KB	Output is correct
2	Correct	3 ms	27904 KB	Output is correct
3	Correct	9 ms	27904 KB	Output is correct
4	Correct	6 ms	27904 KB	Output is correct
5	Correct	3 ms	27904 KB	Output is correct
6	Correct	9 ms	27904 KB	Output is correct
7	Correct	6 ms	27904 KB	Output is correct
8	Correct	3 ms	27904 KB	Output is correct
9	Correct	3 ms	27904 KB	Output is correct
10	Correct	3 ms	27904 KB	Output is correct
11	Correct	6 ms	27904 KB	Output is correct
12	Correct	6 ms	27904 KB	Output is correct
13	Correct	9 ms	27904 KB	Output is correct
14	Correct	13 ms	27904 KB	Output is correct
15	Correct	9 ms	27904 KB	Output is correct
16	Correct	3 ms	27904 KB	Output is correct
17	Correct	3 ms	27904 KB	Output is correct
18	Correct	6 ms	27904 KB	Output is correct
19	Correct	3 ms	27904 KB	Output is correct
20	Correct	3 ms	27904 KB	Output is correct

Subtask #2
45.0 / 45.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	3 ms	27904 KB	Output is correct
2	Correct	3 ms	27904 KB	Output is correct
3	Correct	9 ms	27904 KB	Output is correct
4	Correct	6 ms	27904 KB	Output is correct
5	Correct	3 ms	27904 KB	Output is correct
6	Correct	9 ms	27904 KB	Output is correct
7	Correct	6 ms	27904 KB	Output is correct
8	Correct	3 ms	27904 KB	Output is correct
9	Correct	3 ms	27904 KB	Output is correct
10	Correct	3 ms	27904 KB	Output is correct
11	Correct	6 ms	27904 KB	Output is correct
12	Correct	6 ms	27904 KB	Output is correct
13	Correct	9 ms	27904 KB	Output is correct
14	Correct	13 ms	27904 KB	Output is correct
15	Correct	9 ms	27904 KB	Output is correct
16	Correct	3 ms	27904 KB	Output is correct
17	Correct	3 ms	27904 KB	Output is correct
18	Correct	6 ms	27904 KB	Output is correct
19	Correct	3 ms	27904 KB	Output is correct
20	Correct	3 ms	27904 KB	Output is correct
21	Correct	0 ms	27904 KB	Output is correct
22	Correct	6 ms	28036 KB	Output is correct
23	Correct	3 ms	28036 KB	Output is correct
24	Correct	6 ms	28036 KB	Output is correct
25	Correct	13 ms	28036 KB	Output is correct
26	Correct	3 ms	28036 KB	Output is correct
27	Correct	9 ms	28036 KB	Output is correct
28	Correct	3 ms	28036 KB	Output is correct
29	Correct	13 ms	28036 KB	Output is correct
30	Correct	6 ms	27904 KB	Output is correct
31	Correct	3 ms	28036 KB	Output is correct
32	Correct	3 ms	27904 KB	Output is correct
33	Correct	3 ms	27904 KB	Output is correct
34	Correct	13 ms	27904 KB	Output is correct
35	Correct	3 ms	27904 KB	Output is correct
36	Correct	3 ms	27904 KB	Output is correct
37	Correct	3 ms	27904 KB	Output is correct
38	Correct	0 ms	27904 KB	Output is correct
39	Correct	6 ms	27904 KB	Output is correct
40	Correct	3 ms	27904 KB	Output is correct
41	Correct	9 ms	27904 KB	Output is correct
42	Correct	13 ms	27904 KB	Output is correct
43	Correct	6 ms	28036 KB	Output is correct
44	Correct	6 ms	27904 KB	Output is correct
45	Correct	3 ms	27904 KB	Output is correct
46	Correct	6 ms	27904 KB	Output is correct
47	Correct	6 ms	27904 KB	Output is correct
48	Correct	6 ms	27904 KB	Output is correct
49	Correct	6 ms	28036 KB	Output is correct
50	Correct	3 ms	27904 KB	Output is correct
51	Correct	6 ms	27904 KB	Output is correct
52	Correct	3 ms	27904 KB	Output is correct
53	Correct	9 ms	27904 KB	Output is correct
54	Correct	3 ms	27904 KB	Output is correct
55	Correct	6 ms	27904 KB	Output is correct
56	Correct	6 ms	27904 KB	Output is correct
57	Correct	6 ms	27904 KB	Output is correct
58	Correct	3 ms	28036 KB	Output is correct

Subtask #3
37.0 / 37.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	3 ms	27904 KB	Output is correct
2	Correct	3 ms	27904 KB	Output is correct
3	Correct	9 ms	27904 KB	Output is correct
4	Correct	6 ms	27904 KB	Output is correct
5	Correct	3 ms	27904 KB	Output is correct
6	Correct	9 ms	27904 KB	Output is correct
7	Correct	6 ms	27904 KB	Output is correct
8	Correct	3 ms	27904 KB	Output is correct
9	Correct	3 ms	27904 KB	Output is correct
10	Correct	3 ms	27904 KB	Output is correct
11	Correct	6 ms	27904 KB	Output is correct
12	Correct	6 ms	27904 KB	Output is correct
13	Correct	9 ms	27904 KB	Output is correct
14	Correct	13 ms	27904 KB	Output is correct
15	Correct	9 ms	27904 KB	Output is correct
16	Correct	3 ms	27904 KB	Output is correct
17	Correct	3 ms	27904 KB	Output is correct
18	Correct	6 ms	27904 KB	Output is correct
19	Correct	3 ms	27904 KB	Output is correct
20	Correct	3 ms	27904 KB	Output is correct
21	Correct	0 ms	27904 KB	Output is correct
22	Correct	6 ms	28036 KB	Output is correct
23	Correct	3 ms	28036 KB	Output is correct
24	Correct	6 ms	28036 KB	Output is correct
25	Correct	13 ms	28036 KB	Output is correct
26	Correct	3 ms	28036 KB	Output is correct
27	Correct	9 ms	28036 KB	Output is correct
28	Correct	3 ms	28036 KB	Output is correct
29	Correct	13 ms	28036 KB	Output is correct
30	Correct	6 ms	27904 KB	Output is correct
31	Correct	3 ms	28036 KB	Output is correct
32	Correct	3 ms	27904 KB	Output is correct
33	Correct	3 ms	27904 KB	Output is correct
34	Correct	13 ms	27904 KB	Output is correct
35	Correct	3 ms	27904 KB	Output is correct
36	Correct	3 ms	27904 KB	Output is correct
37	Correct	3 ms	27904 KB	Output is correct
38	Correct	0 ms	27904 KB	Output is correct
39	Correct	6 ms	27904 KB	Output is correct
40	Correct	3 ms	27904 KB	Output is correct
41	Correct	9 ms	27904 KB	Output is correct
42	Correct	13 ms	27904 KB	Output is correct
43	Correct	6 ms	28036 KB	Output is correct
44	Correct	6 ms	27904 KB	Output is correct
45	Correct	3 ms	27904 KB	Output is correct
46	Correct	6 ms	27904 KB	Output is correct
47	Correct	6 ms	27904 KB	Output is correct
48	Correct	6 ms	27904 KB	Output is correct
49	Correct	6 ms	28036 KB	Output is correct
50	Correct	3 ms	27904 KB	Output is correct
51	Correct	6 ms	27904 KB	Output is correct
52	Correct	3 ms	27904 KB	Output is correct
53	Correct	9 ms	27904 KB	Output is correct
54	Correct	3 ms	27904 KB	Output is correct
55	Correct	6 ms	27904 KB	Output is correct
56	Correct	6 ms	27904 KB	Output is correct
57	Correct	6 ms	27904 KB	Output is correct
58	Correct	3 ms	28036 KB	Output is correct
59	Correct	549 ms	48848 KB	Output is correct
60	Correct	616 ms	47496 KB	Output is correct
61	Correct	3 ms	27904 KB	Output is correct
62	Correct	6 ms	27904 KB	Output is correct
63	Correct	483 ms	45180 KB	Output is correct
64	Correct	9 ms	28144 KB	Output is correct
65	Correct	26 ms	29420 KB	Output is correct
66	Correct	279 ms	41416 KB	Output is correct
67	Correct	749 ms	55924 KB	Output is correct
68	Correct	803 ms	56716 KB	Output is correct
69	Correct	16 ms	29032 KB	Output is correct
70	Correct	143 ms	38884 KB	Output is correct
71	Correct	483 ms	63228 KB	Output is correct
72	Correct	473 ms	61308 KB	Output is correct
73	Correct	129 ms	33120 KB	Output is correct
74	Correct	689 ms	46588 KB	Output is correct
75	Correct	39 ms	31068 KB	Output is correct
76	Correct	449 ms	55988 KB	Output is correct
77	Correct	483 ms	56352 KB	Output is correct
78	Correct	49 ms	30528 KB	Output is correct
79	Correct	873 ms	54176 KB	Output is correct
80	Correct	9 ms	28168 KB	Output is correct
81	Correct	143 ms	37172 KB	Output is correct
82	Correct	613 ms	54644 KB	Output is correct
83	Correct	719 ms	46560 KB	Output is correct
84	Correct	689 ms	46956 KB	Output is correct
85	Correct	709 ms	47328 KB	Output is correct
86	Correct	629 ms	47848 KB	Output is correct
87	Correct	703 ms	47876 KB	Output is correct

Submission #22983

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