답안 #716752

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
716752	2023-03-31T02:47:45 Z	Spade1	Network (BOI15_net)	C++14	100 / 100	430 ms	50040 KB

#pragma GCC optimize("O3")
#include<bits/stdc++.h>
//#include <grader.h>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define ll long long
#define ld long double
#define st first
#define nd second
#define pb push_back
#define INF INT_MAX
#define db double
using namespace std;

const int N = 5e5 + 10;

vector<int> v;
vector<int> adj[N];

void dfs(int i, int prt) {
    for (auto j : adj[i]) if (j != prt) dfs(j, i);
    if (adj[i].size() == 1) v.pb(i);
}

void solve() {
    int n; cin >> n;
    for (int i = 1; i < n; ++i) {
        int u, v; cin >> u >> v;
        adj[u].pb(v); adj[v].pb(u);
    }
    int root;
    for (int i = 1; i <= n; ++i) if (adj[i].size() > 1) root = i;
    dfs(root, 0);
    int sz = v.size();
    cout << (sz+1)/2 << '\n';
    for (int i = 0; i < sz/2; ++i) {
        cout << v[i] << " " << v[i+sz/2] << '\n';
    }
    if (sz&1) cout << v[sz-1] << " " << v[0] << '\n';
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(NULL);
    int t = 1;
//    cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}

Compilation message

net.cpp: In function 'void solve()':
net.cpp:31:9: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
   31 |     int root;
      |         ^~~~

Subtask #1
18.0 / 18.0

#	결과	실행 시간	메모리	Grader output
1	Correct	7 ms	11988 KB	Output is correct
2	Correct	8 ms	11988 KB	Output is correct
3	Correct	7 ms	11988 KB	Output is correct
4	Correct	7 ms	11988 KB	Output is correct
5	Correct	8 ms	11992 KB	Output is correct
6	Correct	7 ms	12060 KB	Output is correct
7	Correct	7 ms	11988 KB	Output is correct
8	Correct	7 ms	11988 KB	Output is correct
9	Correct	7 ms	11988 KB	Output is correct
10	Correct	7 ms	11988 KB	Output is correct
11	Correct	8 ms	11988 KB	Output is correct
12	Correct	7 ms	12068 KB	Output is correct
13	Correct	7 ms	12064 KB	Output is correct
14	Correct	7 ms	11988 KB	Output is correct
15	Correct	8 ms	11988 KB	Output is correct
16	Correct	7 ms	11988 KB	Output is correct
17	Correct	8 ms	11964 KB	Output is correct
18	Correct	8 ms	11988 KB	Output is correct
19	Correct	7 ms	11988 KB	Output is correct
20	Correct	7 ms	11988 KB	Output is correct

Subtask #2
45.0 / 45.0

#	결과	실행 시간	메모리	Grader output
1	Correct	7 ms	11988 KB	Output is correct
2	Correct	8 ms	11988 KB	Output is correct
3	Correct	7 ms	11988 KB	Output is correct
4	Correct	7 ms	11988 KB	Output is correct
5	Correct	8 ms	11992 KB	Output is correct
6	Correct	7 ms	12060 KB	Output is correct
7	Correct	7 ms	11988 KB	Output is correct
8	Correct	7 ms	11988 KB	Output is correct
9	Correct	7 ms	11988 KB	Output is correct
10	Correct	7 ms	11988 KB	Output is correct
11	Correct	8 ms	11988 KB	Output is correct
12	Correct	7 ms	12068 KB	Output is correct
13	Correct	7 ms	12064 KB	Output is correct
14	Correct	7 ms	11988 KB	Output is correct
15	Correct	8 ms	11988 KB	Output is correct
16	Correct	7 ms	11988 KB	Output is correct
17	Correct	8 ms	11964 KB	Output is correct
18	Correct	8 ms	11988 KB	Output is correct
19	Correct	7 ms	11988 KB	Output is correct
20	Correct	7 ms	11988 KB	Output is correct
21	Correct	7 ms	11988 KB	Output is correct
22	Correct	8 ms	12076 KB	Output is correct
23	Correct	8 ms	12124 KB	Output is correct
24	Correct	8 ms	12124 KB	Output is correct
25	Correct	8 ms	12052 KB	Output is correct
26	Correct	9 ms	12116 KB	Output is correct
27	Correct	8 ms	12080 KB	Output is correct
28	Correct	8 ms	12072 KB	Output is correct
29	Correct	8 ms	12076 KB	Output is correct
30	Correct	8 ms	12064 KB	Output is correct
31	Correct	8 ms	12100 KB	Output is correct
32	Correct	8 ms	11988 KB	Output is correct
33	Correct	7 ms	11988 KB	Output is correct
34	Correct	8 ms	12000 KB	Output is correct
35	Correct	7 ms	11988 KB	Output is correct
36	Correct	8 ms	11952 KB	Output is correct
37	Correct	8 ms	11988 KB	Output is correct
38	Correct	8 ms	12104 KB	Output is correct
39	Correct	7 ms	11988 KB	Output is correct
40	Correct	7 ms	11988 KB	Output is correct
41	Correct	7 ms	12064 KB	Output is correct
42	Correct	7 ms	12084 KB	Output is correct
43	Correct	7 ms	12064 KB	Output is correct
44	Correct	7 ms	12004 KB	Output is correct
45	Correct	8 ms	11988 KB	Output is correct
46	Correct	8 ms	12068 KB	Output is correct
47	Correct	8 ms	11988 KB	Output is correct
48	Correct	7 ms	11988 KB	Output is correct
49	Correct	7 ms	12116 KB	Output is correct
50	Correct	7 ms	12068 KB	Output is correct
51	Correct	7 ms	12064 KB	Output is correct
52	Correct	7 ms	12064 KB	Output is correct
53	Correct	8 ms	12116 KB	Output is correct
54	Correct	7 ms	12068 KB	Output is correct
55	Correct	7 ms	12064 KB	Output is correct
56	Correct	7 ms	12064 KB	Output is correct
57	Correct	8 ms	12068 KB	Output is correct
58	Correct	8 ms	12160 KB	Output is correct

Subtask #3
37.0 / 37.0

#	결과	실행 시간	메모리	Grader output
1	Correct	7 ms	11988 KB	Output is correct
2	Correct	8 ms	11988 KB	Output is correct
3	Correct	7 ms	11988 KB	Output is correct
4	Correct	7 ms	11988 KB	Output is correct
5	Correct	8 ms	11992 KB	Output is correct
6	Correct	7 ms	12060 KB	Output is correct
7	Correct	7 ms	11988 KB	Output is correct
8	Correct	7 ms	11988 KB	Output is correct
9	Correct	7 ms	11988 KB	Output is correct
10	Correct	7 ms	11988 KB	Output is correct
11	Correct	8 ms	11988 KB	Output is correct
12	Correct	7 ms	12068 KB	Output is correct
13	Correct	7 ms	12064 KB	Output is correct
14	Correct	7 ms	11988 KB	Output is correct
15	Correct	8 ms	11988 KB	Output is correct
16	Correct	7 ms	11988 KB	Output is correct
17	Correct	8 ms	11964 KB	Output is correct
18	Correct	8 ms	11988 KB	Output is correct
19	Correct	7 ms	11988 KB	Output is correct
20	Correct	7 ms	11988 KB	Output is correct
21	Correct	7 ms	11988 KB	Output is correct
22	Correct	8 ms	12076 KB	Output is correct
23	Correct	8 ms	12124 KB	Output is correct
24	Correct	8 ms	12124 KB	Output is correct
25	Correct	8 ms	12052 KB	Output is correct
26	Correct	9 ms	12116 KB	Output is correct
27	Correct	8 ms	12080 KB	Output is correct
28	Correct	8 ms	12072 KB	Output is correct
29	Correct	8 ms	12076 KB	Output is correct
30	Correct	8 ms	12064 KB	Output is correct
31	Correct	8 ms	12100 KB	Output is correct
32	Correct	8 ms	11988 KB	Output is correct
33	Correct	7 ms	11988 KB	Output is correct
34	Correct	8 ms	12000 KB	Output is correct
35	Correct	7 ms	11988 KB	Output is correct
36	Correct	8 ms	11952 KB	Output is correct
37	Correct	8 ms	11988 KB	Output is correct
38	Correct	8 ms	12104 KB	Output is correct
39	Correct	7 ms	11988 KB	Output is correct
40	Correct	7 ms	11988 KB	Output is correct
41	Correct	7 ms	12064 KB	Output is correct
42	Correct	7 ms	12084 KB	Output is correct
43	Correct	7 ms	12064 KB	Output is correct
44	Correct	7 ms	12004 KB	Output is correct
45	Correct	8 ms	11988 KB	Output is correct
46	Correct	8 ms	12068 KB	Output is correct
47	Correct	8 ms	11988 KB	Output is correct
48	Correct	7 ms	11988 KB	Output is correct
49	Correct	7 ms	12116 KB	Output is correct
50	Correct	7 ms	12068 KB	Output is correct
51	Correct	7 ms	12064 KB	Output is correct
52	Correct	7 ms	12064 KB	Output is correct
53	Correct	8 ms	12116 KB	Output is correct
54	Correct	7 ms	12068 KB	Output is correct
55	Correct	7 ms	12064 KB	Output is correct
56	Correct	7 ms	12064 KB	Output is correct
57	Correct	8 ms	12068 KB	Output is correct
58	Correct	8 ms	12160 KB	Output is correct
59	Correct	329 ms	36048 KB	Output is correct
60	Correct	380 ms	38808 KB	Output is correct
61	Correct	7 ms	11988 KB	Output is correct
62	Correct	8 ms	11988 KB	Output is correct
63	Correct	261 ms	33488 KB	Output is correct
64	Correct	9 ms	12372 KB	Output is correct
65	Correct	16 ms	13448 KB	Output is correct
66	Correct	128 ms	23400 KB	Output is correct
67	Correct	414 ms	50040 KB	Output is correct
68	Correct	402 ms	45316 KB	Output is correct
69	Correct	13 ms	12884 KB	Output is correct
70	Correct	79 ms	21188 KB	Output is correct
71	Correct	249 ms	41836 KB	Output is correct
72	Correct	259 ms	40652 KB	Output is correct
73	Correct	68 ms	19020 KB	Output is correct
74	Correct	354 ms	37688 KB	Output is correct
75	Correct	26 ms	15188 KB	Output is correct
76	Correct	272 ms	41592 KB	Output is correct
77	Correct	271 ms	41664 KB	Output is correct
78	Correct	31 ms	15052 KB	Output is correct
79	Correct	393 ms	41440 KB	Output is correct
80	Correct	9 ms	12244 KB	Output is correct
81	Correct	106 ms	21268 KB	Output is correct
82	Correct	327 ms	39528 KB	Output is correct
83	Correct	361 ms	37696 KB	Output is correct
84	Correct	397 ms	37612 KB	Output is correct
85	Correct	369 ms	37600 KB	Output is correct
86	Correct	397 ms	38844 KB	Output is correct
87	Correct	430 ms	38716 KB	Output is correct

답안 #716752

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