답안 #41288 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
41288	2018-02-15T16:13:04 Z	igzi	Network (BOI15_net)	C++14	100 / 100	913 ms	159164 KB

#include <bits/stdc++.h>
#define maxN 500002

using namespace std;

int n,x,y,i,j,l,t,deg[maxN],br[maxN],par[maxN],a[maxN];
bool visited[maxN];
vector <int> adj[maxN];

void dfs1(int n){
int i;
if(deg[n]==1) br[n]=1;
else br[n]=0;
visited[n]=true;
for(i=0;i<adj[n].size();i++){
if(!visited[adj[n][i]]){
    par[adj[n][i]]=n;
    dfs1(adj[n][i]);
    br[n]+=br[adj[n][i]];
}
}
}
void dfs2(int n){
int i;
visited[n]=true;
if(deg[n]==1) {a[t]=n; t++;}
for(i=0;i<adj[n].size();i++){
    if(!visited[adj[n][i]]){
        dfs2(adj[n][i]);
    }
}
}

int main()
{
    std::ios::sync_with_stdio(false);
    l=0;
    cin>>n;
    for(i=1;i<=n;i++){
        deg[i]=0;
    }
    for(i=1;i<n;i++){
        cin>>x>>y;
        adj[x].push_back(y);
        adj[y].push_back(x);
        deg[x]++;
        deg[y]++;
    }
    for(i=1;i<=n;i++){
        if(deg[i]==1) l++;
        visited[i]=false;
    }
    par[1]=1;
    dfs1(1);
    for(i=1;i<=n;i++){
        bool b=true;
        if(l-br[i]>l-l/2) continue;
        for(j=0;j<adj[i].size();j++){
            if(adj[i][j]!=par[i]) b=b && (br[adj[i][j]]<=l-l/2);
        }
    if(b) {x=i; break;}
    }
    t=0;
    for(i=1;i<=n;i++){
        visited[i]=false;
    }
    dfs2(x);
    cout<<l-l/2<<endl;
    for(i=0;i<l-l/2;i++){
        cout<<a[i]<<" "<<a[i+l/2]<<endl;
    }
    return 0;
}

Compilation message

net.cpp: In function 'void dfs1(int)':
net.cpp:15:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 for(i=0;i<adj[n].size();i++){
          ^
net.cpp: In function 'void dfs2(int)':
net.cpp:27:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 for(i=0;i<adj[n].size();i++){
          ^
net.cpp: In function 'int main()':
net.cpp:58:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(j=0;j<adj[i].size();j++){
                  ^

Subtask #1
18.0 / 18.0

#	결과	실행 시간	메모리	Grader output
1	Correct	11 ms	12024 KB	Output is correct
2	Correct	11 ms	12128 KB	Output is correct
3	Correct	11 ms	12164 KB	Output is correct
4	Correct	11 ms	12292 KB	Output is correct
5	Correct	11 ms	12292 KB	Output is correct
6	Correct	11 ms	12292 KB	Output is correct
7	Correct	11 ms	12292 KB	Output is correct
8	Correct	11 ms	12304 KB	Output is correct
9	Correct	11 ms	12304 KB	Output is correct
10	Correct	11 ms	12304 KB	Output is correct
11	Correct	12 ms	12304 KB	Output is correct
12	Correct	14 ms	12304 KB	Output is correct
13	Correct	11 ms	12360 KB	Output is correct
14	Correct	11 ms	12408 KB	Output is correct
15	Correct	10 ms	12408 KB	Output is correct
16	Correct	11 ms	12408 KB	Output is correct
17	Correct	11 ms	12408 KB	Output is correct
18	Correct	10 ms	12408 KB	Output is correct
19	Correct	11 ms	12408 KB	Output is correct
20	Correct	10 ms	12408 KB	Output is correct

Subtask #2
45.0 / 45.0

#	결과	실행 시간	메모리	Grader output
1	Correct	11 ms	12024 KB	Output is correct
2	Correct	11 ms	12128 KB	Output is correct
3	Correct	11 ms	12164 KB	Output is correct
4	Correct	11 ms	12292 KB	Output is correct
5	Correct	11 ms	12292 KB	Output is correct
6	Correct	11 ms	12292 KB	Output is correct
7	Correct	11 ms	12292 KB	Output is correct
8	Correct	11 ms	12304 KB	Output is correct
9	Correct	11 ms	12304 KB	Output is correct
10	Correct	11 ms	12304 KB	Output is correct
11	Correct	12 ms	12304 KB	Output is correct
12	Correct	14 ms	12304 KB	Output is correct
13	Correct	11 ms	12360 KB	Output is correct
14	Correct	11 ms	12408 KB	Output is correct
15	Correct	10 ms	12408 KB	Output is correct
16	Correct	11 ms	12408 KB	Output is correct
17	Correct	11 ms	12408 KB	Output is correct
18	Correct	10 ms	12408 KB	Output is correct
19	Correct	11 ms	12408 KB	Output is correct
20	Correct	10 ms	12408 KB	Output is correct
21	Correct	10 ms	12408 KB	Output is correct
22	Correct	13 ms	12524 KB	Output is correct
23	Correct	13 ms	12524 KB	Output is correct
24	Correct	13 ms	12540 KB	Output is correct
25	Correct	12 ms	12540 KB	Output is correct
26	Correct	12 ms	12540 KB	Output is correct
27	Correct	13 ms	12540 KB	Output is correct
28	Correct	13 ms	12572 KB	Output is correct
29	Correct	12 ms	12572 KB	Output is correct
30	Correct	11 ms	12572 KB	Output is correct
31	Correct	13 ms	12572 KB	Output is correct
32	Correct	10 ms	12572 KB	Output is correct
33	Correct	10 ms	12572 KB	Output is correct
34	Correct	11 ms	12572 KB	Output is correct
35	Correct	11 ms	12572 KB	Output is correct
36	Correct	11 ms	12572 KB	Output is correct
37	Correct	12 ms	12572 KB	Output is correct
38	Correct	11 ms	12572 KB	Output is correct
39	Correct	10 ms	12572 KB	Output is correct
40	Correct	11 ms	12572 KB	Output is correct
41	Correct	11 ms	12572 KB	Output is correct
42	Correct	12 ms	12572 KB	Output is correct
43	Correct	13 ms	12572 KB	Output is correct
44	Correct	11 ms	12572 KB	Output is correct
45	Correct	11 ms	12572 KB	Output is correct
46	Correct	11 ms	12572 KB	Output is correct
47	Correct	9 ms	12572 KB	Output is correct
48	Correct	11 ms	12572 KB	Output is correct
49	Correct	13 ms	12572 KB	Output is correct
50	Correct	11 ms	12572 KB	Output is correct
51	Correct	12 ms	12572 KB	Output is correct
52	Correct	11 ms	12572 KB	Output is correct
53	Correct	11 ms	12572 KB	Output is correct
54	Correct	11 ms	12572 KB	Output is correct
55	Correct	11 ms	12572 KB	Output is correct
56	Correct	11 ms	12572 KB	Output is correct
57	Correct	12 ms	12572 KB	Output is correct
58	Correct	13 ms	12592 KB	Output is correct

Subtask #3
37.0 / 37.0

#	결과	실행 시간	메모리	Grader output
1	Correct	11 ms	12024 KB	Output is correct
2	Correct	11 ms	12128 KB	Output is correct
3	Correct	11 ms	12164 KB	Output is correct
4	Correct	11 ms	12292 KB	Output is correct
5	Correct	11 ms	12292 KB	Output is correct
6	Correct	11 ms	12292 KB	Output is correct
7	Correct	11 ms	12292 KB	Output is correct
8	Correct	11 ms	12304 KB	Output is correct
9	Correct	11 ms	12304 KB	Output is correct
10	Correct	11 ms	12304 KB	Output is correct
11	Correct	12 ms	12304 KB	Output is correct
12	Correct	14 ms	12304 KB	Output is correct
13	Correct	11 ms	12360 KB	Output is correct
14	Correct	11 ms	12408 KB	Output is correct
15	Correct	10 ms	12408 KB	Output is correct
16	Correct	11 ms	12408 KB	Output is correct
17	Correct	11 ms	12408 KB	Output is correct
18	Correct	10 ms	12408 KB	Output is correct
19	Correct	11 ms	12408 KB	Output is correct
20	Correct	10 ms	12408 KB	Output is correct
21	Correct	10 ms	12408 KB	Output is correct
22	Correct	13 ms	12524 KB	Output is correct
23	Correct	13 ms	12524 KB	Output is correct
24	Correct	13 ms	12540 KB	Output is correct
25	Correct	12 ms	12540 KB	Output is correct
26	Correct	12 ms	12540 KB	Output is correct
27	Correct	13 ms	12540 KB	Output is correct
28	Correct	13 ms	12572 KB	Output is correct
29	Correct	12 ms	12572 KB	Output is correct
30	Correct	11 ms	12572 KB	Output is correct
31	Correct	13 ms	12572 KB	Output is correct
32	Correct	10 ms	12572 KB	Output is correct
33	Correct	10 ms	12572 KB	Output is correct
34	Correct	11 ms	12572 KB	Output is correct
35	Correct	11 ms	12572 KB	Output is correct
36	Correct	11 ms	12572 KB	Output is correct
37	Correct	12 ms	12572 KB	Output is correct
38	Correct	11 ms	12572 KB	Output is correct
39	Correct	10 ms	12572 KB	Output is correct
40	Correct	11 ms	12572 KB	Output is correct
41	Correct	11 ms	12572 KB	Output is correct
42	Correct	12 ms	12572 KB	Output is correct
43	Correct	13 ms	12572 KB	Output is correct
44	Correct	11 ms	12572 KB	Output is correct
45	Correct	11 ms	12572 KB	Output is correct
46	Correct	11 ms	12572 KB	Output is correct
47	Correct	9 ms	12572 KB	Output is correct
48	Correct	11 ms	12572 KB	Output is correct
49	Correct	13 ms	12572 KB	Output is correct
50	Correct	11 ms	12572 KB	Output is correct
51	Correct	12 ms	12572 KB	Output is correct
52	Correct	11 ms	12572 KB	Output is correct
53	Correct	11 ms	12572 KB	Output is correct
54	Correct	11 ms	12572 KB	Output is correct
55	Correct	11 ms	12572 KB	Output is correct
56	Correct	11 ms	12572 KB	Output is correct
57	Correct	12 ms	12572 KB	Output is correct
58	Correct	13 ms	12592 KB	Output is correct
59	Correct	777 ms	41968 KB	Output is correct
60	Correct	895 ms	51412 KB	Output is correct
61	Correct	11 ms	51412 KB	Output is correct
62	Correct	11 ms	51412 KB	Output is correct
63	Correct	688 ms	51620 KB	Output is correct
64	Correct	17 ms	51620 KB	Output is correct
65	Correct	28 ms	51620 KB	Output is correct
66	Correct	246 ms	51620 KB	Output is correct
67	Correct	865 ms	74336 KB	Output is correct
68	Correct	913 ms	81636 KB	Output is correct
69	Correct	28 ms	81636 KB	Output is correct
70	Correct	212 ms	81636 KB	Output is correct
71	Correct	772 ms	84560 KB	Output is correct
72	Correct	777 ms	90168 KB	Output is correct
73	Correct	194 ms	90168 KB	Output is correct
74	Correct	823 ms	95012 KB	Output is correct
75	Correct	70 ms	95012 KB	Output is correct
76	Correct	752 ms	106360 KB	Output is correct
77	Correct	730 ms	113148 KB	Output is correct
78	Correct	51 ms	113148 KB	Output is correct
79	Correct	854 ms	123928 KB	Output is correct
80	Correct	15 ms	123928 KB	Output is correct
81	Correct	220 ms	123928 KB	Output is correct
82	Correct	771 ms	126816 KB	Output is correct
83	Correct	870 ms	131556 KB	Output is correct
84	Correct	884 ms	138168 KB	Output is correct
85	Correct	884 ms	144844 KB	Output is correct
86	Correct	908 ms	152488 KB	Output is correct
87	Correct	836 ms	159164 KB	Output is correct

답안 #41288

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