Submission #1008744

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
1008744	2024-06-26T17:22:06 Z	ByeWorld	Network (BOI15_net)	C++14	100 / 100	394 ms	55892 KB

#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
#define ll long long
#define int long long
#define pb push_back
#define fi first
#define se second
#define lf (id<<1)
#define rg ((id<<1)|1)
#define md ((l+r)>>1)
#define ld long double
using namespace std;
typedef pair<int,int> pii;
typedef pair<pii, int> ipii;
const int MAXN = 6e5+10;
const int INF = 1e18+10;
const int LOG = 19;
const int MOD = 1e9+7;
const int SQRT = 450;
const vector<int> NOL = {};
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const vector<int> dx = {1, -1, 0, 0};
const vector<int> dy = {0, 0, 1, -1};

int n;
vector <int> adj[MAXN];
vector <pii> ans;
vector <int> leaf;
int root;

void dfs(int nw, int par){
	if(adj[nw].size()==1) leaf.pb(nw);
	for(auto nx : adj[nw]){
		if(nx==par) continue;
		dfs(nx, nw);
	}
}
signed main(){
	// ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin >> n;
	for(int i=1; i<=n-1; i++){
		int x, y; cin >> x >> y;
		adj[x].pb(y); adj[y].pb(x);
	}
	for(int i=1; i<=n; i++){
		if(adj[i].size()!=1) root = i;
	}

	dfs(root, 0);
	int siz = leaf.size();
	cout << (siz+1)/2 << '\n';
	for(int i=0; i<(siz+1)/2; i++) 
		cout << leaf[i] << ' ' << leaf[i+siz/2] << '\n';
}

Subtask #1
18.0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	14428 KB	Output is correct
2	Correct	6 ms	14428 KB	Output is correct
3	Correct	6 ms	14428 KB	Output is correct
4	Correct	6 ms	14528 KB	Output is correct
5	Correct	7 ms	14424 KB	Output is correct
6	Correct	6 ms	14428 KB	Output is correct
7	Correct	6 ms	14424 KB	Output is correct
8	Correct	6 ms	14424 KB	Output is correct
9	Correct	6 ms	14428 KB	Output is correct
10	Correct	6 ms	14428 KB	Output is correct
11	Correct	6 ms	14428 KB	Output is correct
12	Correct	5 ms	14428 KB	Output is correct
13	Correct	6 ms	14428 KB	Output is correct
14	Correct	6 ms	14476 KB	Output is correct
15	Correct	5 ms	14428 KB	Output is correct
16	Correct	5 ms	14428 KB	Output is correct
17	Correct	6 ms	14468 KB	Output is correct
18	Correct	6 ms	14424 KB	Output is correct
19	Correct	6 ms	14428 KB	Output is correct
20	Correct	5 ms	14360 KB	Output is correct

Subtask #2
45.0 / 45.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	14428 KB	Output is correct
2	Correct	6 ms	14428 KB	Output is correct
3	Correct	6 ms	14428 KB	Output is correct
4	Correct	6 ms	14528 KB	Output is correct
5	Correct	7 ms	14424 KB	Output is correct
6	Correct	6 ms	14428 KB	Output is correct
7	Correct	6 ms	14424 KB	Output is correct
8	Correct	6 ms	14424 KB	Output is correct
9	Correct	6 ms	14428 KB	Output is correct
10	Correct	6 ms	14428 KB	Output is correct
11	Correct	6 ms	14428 KB	Output is correct
12	Correct	5 ms	14428 KB	Output is correct
13	Correct	6 ms	14428 KB	Output is correct
14	Correct	6 ms	14476 KB	Output is correct
15	Correct	5 ms	14428 KB	Output is correct
16	Correct	5 ms	14428 KB	Output is correct
17	Correct	6 ms	14468 KB	Output is correct
18	Correct	6 ms	14424 KB	Output is correct
19	Correct	6 ms	14428 KB	Output is correct
20	Correct	5 ms	14360 KB	Output is correct
21	Correct	6 ms	14428 KB	Output is correct
22	Correct	8 ms	14428 KB	Output is correct
23	Correct	9 ms	14428 KB	Output is correct
24	Correct	7 ms	14428 KB	Output is correct
25	Correct	6 ms	14428 KB	Output is correct
26	Correct	6 ms	14428 KB	Output is correct
27	Correct	7 ms	14568 KB	Output is correct
28	Correct	7 ms	14428 KB	Output is correct
29	Correct	8 ms	14428 KB	Output is correct
30	Correct	7 ms	14428 KB	Output is correct
31	Correct	6 ms	14424 KB	Output is correct
32	Correct	6 ms	14428 KB	Output is correct
33	Correct	5 ms	14428 KB	Output is correct
34	Correct	6 ms	14424 KB	Output is correct
35	Correct	5 ms	14488 KB	Output is correct
36	Correct	5 ms	14428 KB	Output is correct
37	Correct	5 ms	14428 KB	Output is correct
38	Correct	6 ms	14428 KB	Output is correct
39	Correct	6 ms	14428 KB	Output is correct
40	Correct	6 ms	14424 KB	Output is correct
41	Correct	6 ms	14424 KB	Output is correct
42	Correct	6 ms	14428 KB	Output is correct
43	Correct	8 ms	14424 KB	Output is correct
44	Correct	6 ms	14428 KB	Output is correct
45	Correct	7 ms	14428 KB	Output is correct
46	Correct	6 ms	14428 KB	Output is correct
47	Correct	6 ms	14428 KB	Output is correct
48	Correct	5 ms	14428 KB	Output is correct
49	Correct	6 ms	14428 KB	Output is correct
50	Correct	7 ms	14428 KB	Output is correct
51	Correct	6 ms	14428 KB	Output is correct
52	Correct	6 ms	14428 KB	Output is correct
53	Correct	6 ms	14584 KB	Output is correct
54	Correct	6 ms	14428 KB	Output is correct
55	Correct	6 ms	14428 KB	Output is correct
56	Correct	6 ms	14316 KB	Output is correct
57	Correct	6 ms	14568 KB	Output is correct
58	Correct	7 ms	14428 KB	Output is correct

Subtask #3
37.0 / 37.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	14428 KB	Output is correct
2	Correct	6 ms	14428 KB	Output is correct
3	Correct	6 ms	14428 KB	Output is correct
4	Correct	6 ms	14528 KB	Output is correct
5	Correct	7 ms	14424 KB	Output is correct
6	Correct	6 ms	14428 KB	Output is correct
7	Correct	6 ms	14424 KB	Output is correct
8	Correct	6 ms	14424 KB	Output is correct
9	Correct	6 ms	14428 KB	Output is correct
10	Correct	6 ms	14428 KB	Output is correct
11	Correct	6 ms	14428 KB	Output is correct
12	Correct	5 ms	14428 KB	Output is correct
13	Correct	6 ms	14428 KB	Output is correct
14	Correct	6 ms	14476 KB	Output is correct
15	Correct	5 ms	14428 KB	Output is correct
16	Correct	5 ms	14428 KB	Output is correct
17	Correct	6 ms	14468 KB	Output is correct
18	Correct	6 ms	14424 KB	Output is correct
19	Correct	6 ms	14428 KB	Output is correct
20	Correct	5 ms	14360 KB	Output is correct
21	Correct	6 ms	14428 KB	Output is correct
22	Correct	8 ms	14428 KB	Output is correct
23	Correct	9 ms	14428 KB	Output is correct
24	Correct	7 ms	14428 KB	Output is correct
25	Correct	6 ms	14428 KB	Output is correct
26	Correct	6 ms	14428 KB	Output is correct
27	Correct	7 ms	14568 KB	Output is correct
28	Correct	7 ms	14428 KB	Output is correct
29	Correct	8 ms	14428 KB	Output is correct
30	Correct	7 ms	14428 KB	Output is correct
31	Correct	6 ms	14424 KB	Output is correct
32	Correct	6 ms	14428 KB	Output is correct
33	Correct	5 ms	14428 KB	Output is correct
34	Correct	6 ms	14424 KB	Output is correct
35	Correct	5 ms	14488 KB	Output is correct
36	Correct	5 ms	14428 KB	Output is correct
37	Correct	5 ms	14428 KB	Output is correct
38	Correct	6 ms	14428 KB	Output is correct
39	Correct	6 ms	14428 KB	Output is correct
40	Correct	6 ms	14424 KB	Output is correct
41	Correct	6 ms	14424 KB	Output is correct
42	Correct	6 ms	14428 KB	Output is correct
43	Correct	8 ms	14424 KB	Output is correct
44	Correct	6 ms	14428 KB	Output is correct
45	Correct	7 ms	14428 KB	Output is correct
46	Correct	6 ms	14428 KB	Output is correct
47	Correct	6 ms	14428 KB	Output is correct
48	Correct	5 ms	14428 KB	Output is correct
49	Correct	6 ms	14428 KB	Output is correct
50	Correct	7 ms	14428 KB	Output is correct
51	Correct	6 ms	14428 KB	Output is correct
52	Correct	6 ms	14428 KB	Output is correct
53	Correct	6 ms	14584 KB	Output is correct
54	Correct	6 ms	14428 KB	Output is correct
55	Correct	6 ms	14428 KB	Output is correct
56	Correct	6 ms	14316 KB	Output is correct
57	Correct	6 ms	14568 KB	Output is correct
58	Correct	7 ms	14428 KB	Output is correct
59	Correct	349 ms	42816 KB	Output is correct
60	Correct	312 ms	45752 KB	Output is correct
61	Correct	6 ms	14424 KB	Output is correct
62	Correct	6 ms	14368 KB	Output is correct
63	Correct	258 ms	39060 KB	Output is correct
64	Correct	10 ms	14684 KB	Output is correct
65	Correct	17 ms	15964 KB	Output is correct
66	Correct	94 ms	26448 KB	Output is correct
67	Correct	394 ms	55892 KB	Output is correct
68	Correct	377 ms	50892 KB	Output is correct
69	Correct	12 ms	15452 KB	Output is correct
70	Correct	82 ms	25680 KB	Output is correct
71	Correct	254 ms	48176 KB	Output is correct
72	Correct	319 ms	46656 KB	Output is correct
73	Correct	66 ms	22472 KB	Output is correct
74	Correct	317 ms	43468 KB	Output is correct
75	Correct	31 ms	18072 KB	Output is correct
76	Correct	296 ms	47784 KB	Output is correct
77	Correct	285 ms	48040 KB	Output is correct
78	Correct	32 ms	17868 KB	Output is correct
79	Correct	349 ms	45376 KB	Output is correct
80	Correct	8 ms	14936 KB	Output is correct
81	Correct	92 ms	24908 KB	Output is correct
82	Correct	303 ms	45628 KB	Output is correct
83	Correct	331 ms	43460 KB	Output is correct
84	Correct	317 ms	43464 KB	Output is correct
85	Correct	342 ms	43464 KB	Output is correct
86	Correct	362 ms	45688 KB	Output is correct
87	Correct	349 ms	46008 KB	Output is correct

Submission #1008744

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