답안 #233862

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
233862	2020-05-22T04:00:57 Z	LittleFlowers__	Network (BOI15_net)	C++17	100 / 100	1089 ms	91884 KB

#include <bits/stdc++.h>
using namespace std;
#define in ({int x=0;int c=getchar(),n=0;for(;!isdigit(c);c=getchar()) n=(c=='-');for(;isdigit(c);c=getchar()) x=x*10+c-'0';n?-x:x;})
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//mt19937 rng(1012);
int rnd(int l,int r){return l+rng()%(r-l+1);}
#define fasty ios_base::sync_with_stdio(0),cin.tie(0);
#define forinc(a,b,c) for(int a=b,_c=c;a<=_c;++a)
#define fordec(a,b,c) for(int a=b,_c=c;a>=_c;--a)
#define forv(a,b) for(auto&a:b)
#define fi first
#define se second
#define pb push_back
#define ii pair<int,int>
#define mt make_tuple
#define all(a) a.begin(),a.end()
#define reset(f, x) memset(f, x, sizeof(f))
#define bit(x,i) ((x>>(i-1))&1)
#define on(x,i) (x|(1ll<<(i-1)))
#define off(x,i) (x&~(1<<(i-1)))
#define gg exit(0);

const int N=500010;

int n;
vector<int> val;
vector<int> ad[N],adj[N];

vector<ii> ans;

void add(int i,int j){
    adj[i].pb(j);
    adj[j].pb(i);
    ans.pb({i,j});
}

int it,top,scc;
int st[N],ed[N],co[N],w[N],tr[N];

void dfs1(int u){
    st[u]=ed[u]=++it; co[u]=1; w[++top]=u;
    forv(v,ad[u]) if(v!=tr[u]){
        if(co[v]==0){
            tr[v]=u;
            dfs1(v);
            ed[u]=min(ed[u],ed[v]);
        } else if(co[v]==1){
            ed[u]=min(ed[u],st[v]);
        }
    }
    forv(v,adj[u]) if(v!=tr[u]){
        if(co[v]==0){
            tr[v]=u;
            dfs1(v);
            ed[u]=min(ed[u],ed[v]);
        } else if(co[v]==1){
            ed[u]=min(ed[u],st[v]);
        }
    }
    if(st[u]==ed[u]){
        scc++; int v;
        do{
            v=w[top--];
            co[v]=2;
        } while(u!=v);
    }
}

main(){
    #define task "network"
    //freopen(task".inp","r",stdin);
    //freopen(task".out","w",stdout);

    n=in;
    forinc(i,2,n){
        int u=in,v=in;
        ad[u].pb(v);
        ad[v].pb(u);
    }
    forinc(i,1,n) if(ad[i].size()==1) val.push_back(i);

    for(;;){
        shuffle(all(val),rng);
        for(int l=0;l+1<val.size();l+=2)
            add(val[l],val[l+1]);
        if(val.size()&1)
            add(val[0],val.back());
        dfs1(1);
        if(scc==1)
            break;
        ans.clear(); it=top=scc=0;
        forinc(i,1,n){
            co[i]=tr[i]=0;
            adj[i].clear();
        }
    }
    //cout<<1;
    //gg
    cout<<ans.size()<<"\n";
    forv(i,ans) cout<<i.fi<<" "<<i.se<<"\n";


}

Compilation message

net.cpp:69:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^
net.cpp: In function 'int main()':
net.cpp:84:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int l=0;l+1<val.size();l+=2)
                     ~~~^~~~~~~~~~~

Subtask #1
18.0 / 18.0

#	결과	실행 시간	메모리	Grader output
1	Correct	18 ms	23808 KB	Output is correct
2	Correct	18 ms	23808 KB	Output is correct
3	Correct	19 ms	23936 KB	Output is correct
4	Correct	18 ms	23808 KB	Output is correct
5	Correct	18 ms	23808 KB	Output is correct
6	Correct	18 ms	23680 KB	Output is correct
7	Correct	19 ms	23808 KB	Output is correct
8	Correct	18 ms	23936 KB	Output is correct
9	Correct	18 ms	23808 KB	Output is correct
10	Correct	18 ms	23808 KB	Output is correct
11	Correct	20 ms	23808 KB	Output is correct
12	Correct	18 ms	23808 KB	Output is correct
13	Correct	18 ms	23808 KB	Output is correct
14	Correct	19 ms	23808 KB	Output is correct
15	Correct	18 ms	23808 KB	Output is correct
16	Correct	19 ms	23808 KB	Output is correct
17	Correct	18 ms	23808 KB	Output is correct
18	Correct	18 ms	23808 KB	Output is correct
19	Correct	18 ms	23808 KB	Output is correct
20	Correct	18 ms	23808 KB	Output is correct

Subtask #2
45.0 / 45.0

#	결과	실행 시간	메모리	Grader output
1	Correct	18 ms	23808 KB	Output is correct
2	Correct	18 ms	23808 KB	Output is correct
3	Correct	19 ms	23936 KB	Output is correct
4	Correct	18 ms	23808 KB	Output is correct
5	Correct	18 ms	23808 KB	Output is correct
6	Correct	18 ms	23680 KB	Output is correct
7	Correct	19 ms	23808 KB	Output is correct
8	Correct	18 ms	23936 KB	Output is correct
9	Correct	18 ms	23808 KB	Output is correct
10	Correct	18 ms	23808 KB	Output is correct
11	Correct	20 ms	23808 KB	Output is correct
12	Correct	18 ms	23808 KB	Output is correct
13	Correct	18 ms	23808 KB	Output is correct
14	Correct	19 ms	23808 KB	Output is correct
15	Correct	18 ms	23808 KB	Output is correct
16	Correct	19 ms	23808 KB	Output is correct
17	Correct	18 ms	23808 KB	Output is correct
18	Correct	18 ms	23808 KB	Output is correct
19	Correct	18 ms	23808 KB	Output is correct
20	Correct	18 ms	23808 KB	Output is correct
21	Correct	18 ms	23808 KB	Output is correct
22	Correct	19 ms	24064 KB	Output is correct
23	Correct	19 ms	24064 KB	Output is correct
24	Correct	19 ms	24064 KB	Output is correct
25	Correct	19 ms	24320 KB	Output is correct
26	Correct	19 ms	23936 KB	Output is correct
27	Correct	19 ms	24064 KB	Output is correct
28	Correct	21 ms	24064 KB	Output is correct
29	Correct	20 ms	24064 KB	Output is correct
30	Correct	18 ms	23840 KB	Output is correct
31	Correct	19 ms	24192 KB	Output is correct
32	Correct	18 ms	23808 KB	Output is correct
33	Correct	18 ms	23936 KB	Output is correct
34	Correct	18 ms	23808 KB	Output is correct
35	Correct	18 ms	23808 KB	Output is correct
36	Correct	18 ms	23808 KB	Output is correct
37	Correct	18 ms	23936 KB	Output is correct
38	Correct	19 ms	23936 KB	Output is correct
39	Correct	18 ms	23808 KB	Output is correct
40	Correct	18 ms	23808 KB	Output is correct
41	Correct	18 ms	23808 KB	Output is correct
42	Correct	18 ms	23936 KB	Output is correct
43	Correct	19 ms	23936 KB	Output is correct
44	Correct	19 ms	23808 KB	Output is correct
45	Correct	20 ms	23928 KB	Output is correct
46	Correct	18 ms	23936 KB	Output is correct
47	Correct	18 ms	23936 KB	Output is correct
48	Correct	18 ms	23808 KB	Output is correct
49	Correct	18 ms	24064 KB	Output is correct
50	Correct	18 ms	23808 KB	Output is correct
51	Correct	18 ms	23808 KB	Output is correct
52	Correct	18 ms	23936 KB	Output is correct
53	Correct	19 ms	23936 KB	Output is correct
54	Correct	18 ms	23936 KB	Output is correct
55	Correct	18 ms	23936 KB	Output is correct
56	Correct	18 ms	23808 KB	Output is correct
57	Correct	18 ms	23936 KB	Output is correct
58	Correct	19 ms	24064 KB	Output is correct

Subtask #3
37.0 / 37.0

#	결과	실행 시간	메모리	Grader output
1	Correct	18 ms	23808 KB	Output is correct
2	Correct	18 ms	23808 KB	Output is correct
3	Correct	19 ms	23936 KB	Output is correct
4	Correct	18 ms	23808 KB	Output is correct
5	Correct	18 ms	23808 KB	Output is correct
6	Correct	18 ms	23680 KB	Output is correct
7	Correct	19 ms	23808 KB	Output is correct
8	Correct	18 ms	23936 KB	Output is correct
9	Correct	18 ms	23808 KB	Output is correct
10	Correct	18 ms	23808 KB	Output is correct
11	Correct	20 ms	23808 KB	Output is correct
12	Correct	18 ms	23808 KB	Output is correct
13	Correct	18 ms	23808 KB	Output is correct
14	Correct	19 ms	23808 KB	Output is correct
15	Correct	18 ms	23808 KB	Output is correct
16	Correct	19 ms	23808 KB	Output is correct
17	Correct	18 ms	23808 KB	Output is correct
18	Correct	18 ms	23808 KB	Output is correct
19	Correct	18 ms	23808 KB	Output is correct
20	Correct	18 ms	23808 KB	Output is correct
21	Correct	18 ms	23808 KB	Output is correct
22	Correct	19 ms	24064 KB	Output is correct
23	Correct	19 ms	24064 KB	Output is correct
24	Correct	19 ms	24064 KB	Output is correct
25	Correct	19 ms	24320 KB	Output is correct
26	Correct	19 ms	23936 KB	Output is correct
27	Correct	19 ms	24064 KB	Output is correct
28	Correct	21 ms	24064 KB	Output is correct
29	Correct	20 ms	24064 KB	Output is correct
30	Correct	18 ms	23840 KB	Output is correct
31	Correct	19 ms	24192 KB	Output is correct
32	Correct	18 ms	23808 KB	Output is correct
33	Correct	18 ms	23936 KB	Output is correct
34	Correct	18 ms	23808 KB	Output is correct
35	Correct	18 ms	23808 KB	Output is correct
36	Correct	18 ms	23808 KB	Output is correct
37	Correct	18 ms	23936 KB	Output is correct
38	Correct	19 ms	23936 KB	Output is correct
39	Correct	18 ms	23808 KB	Output is correct
40	Correct	18 ms	23808 KB	Output is correct
41	Correct	18 ms	23808 KB	Output is correct
42	Correct	18 ms	23936 KB	Output is correct
43	Correct	19 ms	23936 KB	Output is correct
44	Correct	19 ms	23808 KB	Output is correct
45	Correct	20 ms	23928 KB	Output is correct
46	Correct	18 ms	23936 KB	Output is correct
47	Correct	18 ms	23936 KB	Output is correct
48	Correct	18 ms	23808 KB	Output is correct
49	Correct	18 ms	24064 KB	Output is correct
50	Correct	18 ms	23808 KB	Output is correct
51	Correct	18 ms	23808 KB	Output is correct
52	Correct	18 ms	23936 KB	Output is correct
53	Correct	19 ms	23936 KB	Output is correct
54	Correct	18 ms	23936 KB	Output is correct
55	Correct	18 ms	23936 KB	Output is correct
56	Correct	18 ms	23808 KB	Output is correct
57	Correct	18 ms	23936 KB	Output is correct
58	Correct	19 ms	24064 KB	Output is correct
59	Correct	750 ms	91884 KB	Output is correct
60	Correct	644 ms	87144 KB	Output is correct
61	Correct	18 ms	23808 KB	Output is correct
62	Correct	18 ms	23808 KB	Output is correct
63	Correct	488 ms	77800 KB	Output is correct
64	Correct	20 ms	24320 KB	Output is correct
65	Correct	27 ms	26112 KB	Output is correct
66	Correct	163 ms	41464 KB	Output is correct
67	Correct	524 ms	87288 KB	Output is correct
68	Correct	537 ms	73844 KB	Output is correct
69	Correct	26 ms	25472 KB	Output is correct
70	Correct	136 ms	41196 KB	Output is correct
71	Correct	511 ms	80992 KB	Output is correct
72	Correct	508 ms	78120 KB	Output is correct
73	Correct	130 ms	39920 KB	Output is correct
74	Correct	853 ms	82032 KB	Output is correct
75	Correct	51 ms	29940 KB	Output is correct
76	Correct	532 ms	79952 KB	Output is correct
77	Correct	528 ms	80848 KB	Output is correct
78	Correct	48 ms	29688 KB	Output is correct
79	Correct	534 ms	81016 KB	Output is correct
80	Correct	21 ms	24320 KB	Output is correct
81	Correct	154 ms	41968 KB	Output is correct
82	Correct	558 ms	77540 KB	Output is correct
83	Correct	653 ms	82248 KB	Output is correct
84	Correct	618 ms	82108 KB	Output is correct
85	Correct	637 ms	82120 KB	Output is correct
86	Correct	1089 ms	87600 KB	Output is correct
87	Correct	644 ms	87400 KB	Output is correct

답안 #233862

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