답안 #165763

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
165763	2019-11-28T13:48:07 Z	jovan_b	Network (BOI15_net)	C++17	100 / 100	773 ms	50284 KB

#include <bits/stdc++.h>
using namespace std;
 
int ukup=0;
int leafs=0;
int leafs1=0;
vector <int> graf[500005];
bool visited[500005];
int listovi[500005];
int brlist[500005];
 
void dfs1(int v){
    visited[v] = 1;
    bool nes = 0;
    for(auto c : graf[v]){
        if(!visited[c]){dfs1(c); nes=1; brlist[v] += brlist[c];}
    }
    if(nes == 0) {leafs++; brlist[v] = 1;}
}
 
void dfs3(int v){
    visited[v] = 1;
    bool nes = 0;
    for(auto c : graf[v]){
        if(!visited[c]){dfs3(c); nes=1;}
    }
    if(nes == 0){leafs++; listovi[leafs] = v;}
}
 
int main(){
    ios_base::sync_with_stdio(false),cin.tie(0),cerr.tie(0),cout.tie(0);
    cout.precision(10);
    cout<<fixed;
 
    int n;
    cin >> n;
    for(int i=1; i<n; i++){
        int a, b;
        cin >> a >> b;
        graf[a].push_back(b);
        graf[b].push_back(a);
    }
    if(n == 2){cout << "1\n 1 2"; return 0;}
    dfs1(1);
    int x = 1;
    for(auto c : graf[1]){
        if(brlist[c] > (brlist[1]/2)){
            x = c;
            int par;
            par = 1;
            while(1){
                if(graf[x].size() != 2) break;
                for(auto nesto : graf[x]){
                    if(nesto != par){par = x; x = nesto; break;}
                }
            }
            break;
        }
    }
    leafs = 0;
    for(int i=1; i<=n; i++) visited[i] = 0;
    dfs3(x);
    int r = 1;
    int br=0;
    while(r+(leafs/2) <= leafs){
        br++;
        r++;
    }
    r = 1;
    cout << br << "\n";
    while(r+(leafs/2) <= leafs){
        cout << listovi[r] << " " << listovi[r+(leafs/2)] << "\n";
        r++;
    }
    return 0;
}

Subtask #1
18.0 / 18.0

#	결과	실행 시간	메모리	Grader output
1	Correct	13 ms	12280 KB	Output is correct
2	Correct	25 ms	12152 KB	Output is correct
3	Correct	13 ms	12152 KB	Output is correct
4	Correct	13 ms	12152 KB	Output is correct
5	Correct	13 ms	12152 KB	Output is correct
6	Correct	12 ms	12152 KB	Output is correct
7	Correct	13 ms	12024 KB	Output is correct
8	Correct	12 ms	12024 KB	Output is correct
9	Correct	15 ms	12152 KB	Output is correct
10	Correct	15 ms	12024 KB	Output is correct
11	Correct	13 ms	12024 KB	Output is correct
12	Correct	13 ms	12152 KB	Output is correct
13	Correct	13 ms	12152 KB	Output is correct
14	Correct	12 ms	12024 KB	Output is correct
15	Correct	16 ms	12024 KB	Output is correct
16	Correct	12 ms	12028 KB	Output is correct
17	Correct	13 ms	12024 KB	Output is correct
18	Correct	13 ms	12152 KB	Output is correct
19	Correct	15 ms	12152 KB	Output is correct
20	Correct	16 ms	12152 KB	Output is correct

Subtask #2
45.0 / 45.0

#	결과	실행 시간	메모리	Grader output
1	Correct	13 ms	12280 KB	Output is correct
2	Correct	25 ms	12152 KB	Output is correct
3	Correct	13 ms	12152 KB	Output is correct
4	Correct	13 ms	12152 KB	Output is correct
5	Correct	13 ms	12152 KB	Output is correct
6	Correct	12 ms	12152 KB	Output is correct
7	Correct	13 ms	12024 KB	Output is correct
8	Correct	12 ms	12024 KB	Output is correct
9	Correct	15 ms	12152 KB	Output is correct
10	Correct	15 ms	12024 KB	Output is correct
11	Correct	13 ms	12024 KB	Output is correct
12	Correct	13 ms	12152 KB	Output is correct
13	Correct	13 ms	12152 KB	Output is correct
14	Correct	12 ms	12024 KB	Output is correct
15	Correct	16 ms	12024 KB	Output is correct
16	Correct	12 ms	12028 KB	Output is correct
17	Correct	13 ms	12024 KB	Output is correct
18	Correct	13 ms	12152 KB	Output is correct
19	Correct	15 ms	12152 KB	Output is correct
20	Correct	16 ms	12152 KB	Output is correct
21	Correct	13 ms	12280 KB	Output is correct
22	Correct	14 ms	12308 KB	Output is correct
23	Correct	14 ms	12156 KB	Output is correct
24	Correct	13 ms	12152 KB	Output is correct
25	Correct	14 ms	12280 KB	Output is correct
26	Correct	14 ms	12152 KB	Output is correct
27	Correct	14 ms	12152 KB	Output is correct
28	Correct	13 ms	12152 KB	Output is correct
29	Correct	14 ms	12280 KB	Output is correct
30	Correct	13 ms	12020 KB	Output is correct
31	Correct	14 ms	12280 KB	Output is correct
32	Correct	13 ms	12152 KB	Output is correct
33	Correct	13 ms	12152 KB	Output is correct
34	Correct	13 ms	12156 KB	Output is correct
35	Correct	13 ms	12180 KB	Output is correct
36	Correct	13 ms	12152 KB	Output is correct
37	Correct	13 ms	12152 KB	Output is correct
38	Correct	12 ms	12156 KB	Output is correct
39	Correct	13 ms	12152 KB	Output is correct
40	Correct	14 ms	12152 KB	Output is correct
41	Correct	12 ms	12152 KB	Output is correct
42	Correct	13 ms	12152 KB	Output is correct
43	Correct	12 ms	12152 KB	Output is correct
44	Correct	13 ms	12152 KB	Output is correct
45	Correct	13 ms	12152 KB	Output is correct
46	Correct	13 ms	12124 KB	Output is correct
47	Correct	13 ms	12024 KB	Output is correct
48	Correct	13 ms	12152 KB	Output is correct
49	Correct	14 ms	12152 KB	Output is correct
50	Correct	13 ms	12152 KB	Output is correct
51	Correct	12 ms	12024 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	12152 KB	Output is correct
55	Correct	14 ms	12152 KB	Output is correct
56	Correct	15 ms	12152 KB	Output is correct
57	Correct	15 ms	12152 KB	Output is correct
58	Correct	15 ms	12284 KB	Output is correct

Subtask #3
37.0 / 37.0

#	결과	실행 시간	메모리	Grader output
1	Correct	13 ms	12280 KB	Output is correct
2	Correct	25 ms	12152 KB	Output is correct
3	Correct	13 ms	12152 KB	Output is correct
4	Correct	13 ms	12152 KB	Output is correct
5	Correct	13 ms	12152 KB	Output is correct
6	Correct	12 ms	12152 KB	Output is correct
7	Correct	13 ms	12024 KB	Output is correct
8	Correct	12 ms	12024 KB	Output is correct
9	Correct	15 ms	12152 KB	Output is correct
10	Correct	15 ms	12024 KB	Output is correct
11	Correct	13 ms	12024 KB	Output is correct
12	Correct	13 ms	12152 KB	Output is correct
13	Correct	13 ms	12152 KB	Output is correct
14	Correct	12 ms	12024 KB	Output is correct
15	Correct	16 ms	12024 KB	Output is correct
16	Correct	12 ms	12028 KB	Output is correct
17	Correct	13 ms	12024 KB	Output is correct
18	Correct	13 ms	12152 KB	Output is correct
19	Correct	15 ms	12152 KB	Output is correct
20	Correct	16 ms	12152 KB	Output is correct
21	Correct	13 ms	12280 KB	Output is correct
22	Correct	14 ms	12308 KB	Output is correct
23	Correct	14 ms	12156 KB	Output is correct
24	Correct	13 ms	12152 KB	Output is correct
25	Correct	14 ms	12280 KB	Output is correct
26	Correct	14 ms	12152 KB	Output is correct
27	Correct	14 ms	12152 KB	Output is correct
28	Correct	13 ms	12152 KB	Output is correct
29	Correct	14 ms	12280 KB	Output is correct
30	Correct	13 ms	12020 KB	Output is correct
31	Correct	14 ms	12280 KB	Output is correct
32	Correct	13 ms	12152 KB	Output is correct
33	Correct	13 ms	12152 KB	Output is correct
34	Correct	13 ms	12156 KB	Output is correct
35	Correct	13 ms	12180 KB	Output is correct
36	Correct	13 ms	12152 KB	Output is correct
37	Correct	13 ms	12152 KB	Output is correct
38	Correct	12 ms	12156 KB	Output is correct
39	Correct	13 ms	12152 KB	Output is correct
40	Correct	14 ms	12152 KB	Output is correct
41	Correct	12 ms	12152 KB	Output is correct
42	Correct	13 ms	12152 KB	Output is correct
43	Correct	12 ms	12152 KB	Output is correct
44	Correct	13 ms	12152 KB	Output is correct
45	Correct	13 ms	12152 KB	Output is correct
46	Correct	13 ms	12124 KB	Output is correct
47	Correct	13 ms	12024 KB	Output is correct
48	Correct	13 ms	12152 KB	Output is correct
49	Correct	14 ms	12152 KB	Output is correct
50	Correct	13 ms	12152 KB	Output is correct
51	Correct	12 ms	12024 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	12152 KB	Output is correct
55	Correct	14 ms	12152 KB	Output is correct
56	Correct	15 ms	12152 KB	Output is correct
57	Correct	15 ms	12152 KB	Output is correct
58	Correct	15 ms	12284 KB	Output is correct
59	Correct	470 ms	38360 KB	Output is correct
60	Correct	632 ms	41160 KB	Output is correct
61	Correct	13 ms	12152 KB	Output is correct
62	Correct	27 ms	12280 KB	Output is correct
63	Correct	398 ms	35568 KB	Output is correct
64	Correct	16 ms	12536 KB	Output is correct
65	Correct	28 ms	14072 KB	Output is correct
66	Correct	227 ms	29024 KB	Output is correct
67	Correct	724 ms	49556 KB	Output is correct
68	Correct	773 ms	50284 KB	Output is correct
69	Correct	22 ms	13048 KB	Output is correct
70	Correct	125 ms	22100 KB	Output is correct
71	Correct	373 ms	44260 KB	Output is correct
72	Correct	462 ms	43116 KB	Output is correct
73	Correct	145 ms	19832 KB	Output is correct
74	Correct	687 ms	40304 KB	Output is correct
75	Correct	46 ms	15736 KB	Output is correct
76	Correct	415 ms	44128 KB	Output is correct
77	Correct	375 ms	44140 KB	Output is correct
78	Correct	50 ms	15608 KB	Output is correct
79	Correct	755 ms	47864 KB	Output is correct
80	Correct	16 ms	12280 KB	Output is correct
81	Correct	159 ms	22000 KB	Output is correct
82	Correct	475 ms	42160 KB	Output is correct
83	Correct	632 ms	40240 KB	Output is correct
84	Correct	594 ms	40184 KB	Output is correct
85	Correct	630 ms	40084 KB	Output is correct
86	Correct	631 ms	41344 KB	Output is correct
87	Correct	538 ms	41232 KB	Output is correct

답안 #165763

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