Submission #394608

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
394608	2021-04-27T05:47:57 Z	RohamIzadidoost	Network (BOI15_net)	C++14	100 / 100	792 ms	45136 KB

#pragma GCC optimize("Ofast,unroll-loops,fast-math")
#include<bits/stdc++.h>
using namespace std;
typedef long long ll ;
#define pll pair<ll , ll >
#define all(x) (x).begin(),(x).end()
#define SZ(x) (ll)(x).size()
#define X   first
#define Y   second
#define mp  make_pair
#define pii pair<int , int>
#define vec vector
#define file_io freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout);
#define migmig ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define pb push_back
#define ld long double
// BIG p : 1000000000000037 , 100000000003
ll poww(ll a, ll b, ll md) {
    return (!b ? 1 : (b & 1 ? a * poww(a * a % md, b / 2, md) % md : poww(a * a % md, b / 2, md) % md));
}
const int maxn = 5000*100+5 ;
const ll inf = 9223372036854775807 ;
const ll mod = 1e9 + 7 ;
const int lg = 20 ;
int n , nl , st[maxn]  , cnt , mark[maxn];
vec<pii> l ; 
vec<int> adj[maxn] ; 
void dfs(int v ){
	st[v] = cnt ++; 
	mark[v] = 1 ; 
	for(auto u : adj[v]) if(!mark[u]) dfs(u) ;
}
int main()
{
	migmig ;
	cin>>n ; 
	for(int i = 1 ; i < n ; i ++ ){
		int u , v ; 
		cin>>u>>v ; 
		adj[u].pb(v) ;
		adj[v].pb(u) ; 
	}
	for(int i = 1 ; i <= n ; i ++ ){
		if(adj[i].size() != 1){
			dfs(i) ; 
			break ; 
		}
	}
	vec<pii> v ; 
	for(int i = 1 ; i <= n ; i ++ ){
		if(SZ(adj[i]) == 1){
			nl ++ ; 
			v.pb({st[i] , i}) ; 
		}
	}
	sort(all(v)) ; 
	cout<<(nl + 1 ) / 2 <<endl ; 
	nl = (nl + 1) / 2 ; 
	for(int i = 0 ; i + nl < SZ(v) ; i ++ ){
		cout<<v[i].Y <<" " << v[i + nl].Y << endl ; 
	}
	if(SZ(v) % 2 == 1){
		cout<<v[nl-1].Y <<" " << v[0].Y << endl ; 
	}
}

Subtask #1
18.0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	9 ms	11980 KB	Output is correct
2	Correct	9 ms	11980 KB	Output is correct
3	Correct	9 ms	11980 KB	Output is correct
4	Correct	9 ms	11984 KB	Output is correct
5	Correct	10 ms	11980 KB	Output is correct
6	Correct	9 ms	11980 KB	Output is correct
7	Correct	9 ms	12040 KB	Output is correct
8	Correct	10 ms	12056 KB	Output is correct
9	Correct	10 ms	12032 KB	Output is correct
10	Correct	9 ms	11980 KB	Output is correct
11	Correct	9 ms	11980 KB	Output is correct
12	Correct	9 ms	11984 KB	Output is correct
13	Correct	9 ms	11980 KB	Output is correct
14	Correct	8 ms	11980 KB	Output is correct
15	Correct	8 ms	11980 KB	Output is correct
16	Correct	10 ms	12000 KB	Output is correct
17	Correct	8 ms	11980 KB	Output is correct
18	Correct	10 ms	11980 KB	Output is correct
19	Correct	9 ms	11980 KB	Output is correct
20	Correct	11 ms	11980 KB	Output is correct

Subtask #2
45.0 / 45.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	9 ms	11980 KB	Output is correct
2	Correct	9 ms	11980 KB	Output is correct
3	Correct	9 ms	11980 KB	Output is correct
4	Correct	9 ms	11984 KB	Output is correct
5	Correct	10 ms	11980 KB	Output is correct
6	Correct	9 ms	11980 KB	Output is correct
7	Correct	9 ms	12040 KB	Output is correct
8	Correct	10 ms	12056 KB	Output is correct
9	Correct	10 ms	12032 KB	Output is correct
10	Correct	9 ms	11980 KB	Output is correct
11	Correct	9 ms	11980 KB	Output is correct
12	Correct	9 ms	11984 KB	Output is correct
13	Correct	9 ms	11980 KB	Output is correct
14	Correct	8 ms	11980 KB	Output is correct
15	Correct	8 ms	11980 KB	Output is correct
16	Correct	10 ms	12000 KB	Output is correct
17	Correct	8 ms	11980 KB	Output is correct
18	Correct	10 ms	11980 KB	Output is correct
19	Correct	9 ms	11980 KB	Output is correct
20	Correct	11 ms	11980 KB	Output is correct
21	Correct	8 ms	12064 KB	Output is correct
22	Correct	13 ms	12108 KB	Output is correct
23	Correct	11 ms	12108 KB	Output is correct
24	Correct	10 ms	12108 KB	Output is correct
25	Correct	22 ms	12108 KB	Output is correct
26	Correct	10 ms	12128 KB	Output is correct
27	Correct	11 ms	12124 KB	Output is correct
28	Correct	11 ms	12068 KB	Output is correct
29	Correct	10 ms	12108 KB	Output is correct
30	Correct	8 ms	11980 KB	Output is correct
31	Correct	10 ms	12108 KB	Output is correct
32	Correct	9 ms	12000 KB	Output is correct
33	Correct	9 ms	11980 KB	Output is correct
34	Correct	8 ms	11980 KB	Output is correct
35	Correct	10 ms	11980 KB	Output is correct
36	Correct	8 ms	12000 KB	Output is correct
37	Correct	9 ms	12120 KB	Output is correct
38	Correct	9 ms	12108 KB	Output is correct
39	Correct	10 ms	11980 KB	Output is correct
40	Correct	10 ms	11980 KB	Output is correct
41	Correct	8 ms	11980 KB	Output is correct
42	Correct	9 ms	12108 KB	Output is correct
43	Correct	9 ms	12108 KB	Output is correct
44	Correct	8 ms	12020 KB	Output is correct
45	Correct	9 ms	12080 KB	Output is correct
46	Correct	9 ms	12108 KB	Output is correct
47	Correct	8 ms	12064 KB	Output is correct
48	Correct	9 ms	11980 KB	Output is correct
49	Correct	9 ms	12108 KB	Output is correct
50	Correct	9 ms	11980 KB	Output is correct
51	Correct	10 ms	12064 KB	Output is correct
52	Correct	9 ms	11980 KB	Output is correct
53	Correct	9 ms	12036 KB	Output is correct
54	Correct	8 ms	11980 KB	Output is correct
55	Correct	9 ms	11980 KB	Output is correct
56	Correct	9 ms	11980 KB	Output is correct
57	Correct	9 ms	11980 KB	Output is correct
58	Correct	11 ms	12108 KB	Output is correct

Subtask #3
37.0 / 37.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	9 ms	11980 KB	Output is correct
2	Correct	9 ms	11980 KB	Output is correct
3	Correct	9 ms	11980 KB	Output is correct
4	Correct	9 ms	11984 KB	Output is correct
5	Correct	10 ms	11980 KB	Output is correct
6	Correct	9 ms	11980 KB	Output is correct
7	Correct	9 ms	12040 KB	Output is correct
8	Correct	10 ms	12056 KB	Output is correct
9	Correct	10 ms	12032 KB	Output is correct
10	Correct	9 ms	11980 KB	Output is correct
11	Correct	9 ms	11980 KB	Output is correct
12	Correct	9 ms	11984 KB	Output is correct
13	Correct	9 ms	11980 KB	Output is correct
14	Correct	8 ms	11980 KB	Output is correct
15	Correct	8 ms	11980 KB	Output is correct
16	Correct	10 ms	12000 KB	Output is correct
17	Correct	8 ms	11980 KB	Output is correct
18	Correct	10 ms	11980 KB	Output is correct
19	Correct	9 ms	11980 KB	Output is correct
20	Correct	11 ms	11980 KB	Output is correct
21	Correct	8 ms	12064 KB	Output is correct
22	Correct	13 ms	12108 KB	Output is correct
23	Correct	11 ms	12108 KB	Output is correct
24	Correct	10 ms	12108 KB	Output is correct
25	Correct	22 ms	12108 KB	Output is correct
26	Correct	10 ms	12128 KB	Output is correct
27	Correct	11 ms	12124 KB	Output is correct
28	Correct	11 ms	12068 KB	Output is correct
29	Correct	10 ms	12108 KB	Output is correct
30	Correct	8 ms	11980 KB	Output is correct
31	Correct	10 ms	12108 KB	Output is correct
32	Correct	9 ms	12000 KB	Output is correct
33	Correct	9 ms	11980 KB	Output is correct
34	Correct	8 ms	11980 KB	Output is correct
35	Correct	10 ms	11980 KB	Output is correct
36	Correct	8 ms	12000 KB	Output is correct
37	Correct	9 ms	12120 KB	Output is correct
38	Correct	9 ms	12108 KB	Output is correct
39	Correct	10 ms	11980 KB	Output is correct
40	Correct	10 ms	11980 KB	Output is correct
41	Correct	8 ms	11980 KB	Output is correct
42	Correct	9 ms	12108 KB	Output is correct
43	Correct	9 ms	12108 KB	Output is correct
44	Correct	8 ms	12020 KB	Output is correct
45	Correct	9 ms	12080 KB	Output is correct
46	Correct	9 ms	12108 KB	Output is correct
47	Correct	8 ms	12064 KB	Output is correct
48	Correct	9 ms	11980 KB	Output is correct
49	Correct	9 ms	12108 KB	Output is correct
50	Correct	9 ms	11980 KB	Output is correct
51	Correct	10 ms	12064 KB	Output is correct
52	Correct	9 ms	11980 KB	Output is correct
53	Correct	9 ms	12036 KB	Output is correct
54	Correct	8 ms	11980 KB	Output is correct
55	Correct	9 ms	11980 KB	Output is correct
56	Correct	9 ms	11980 KB	Output is correct
57	Correct	9 ms	11980 KB	Output is correct
58	Correct	11 ms	12108 KB	Output is correct
59	Correct	677 ms	34680 KB	Output is correct
60	Correct	776 ms	37312 KB	Output is correct
61	Correct	8 ms	11980 KB	Output is correct
62	Correct	8 ms	11980 KB	Output is correct
63	Correct	669 ms	32608 KB	Output is correct
64	Correct	10 ms	12492 KB	Output is correct
65	Correct	20 ms	13804 KB	Output is correct
66	Correct	169 ms	27072 KB	Output is correct
67	Correct	568 ms	44228 KB	Output is correct
68	Correct	575 ms	45136 KB	Output is correct
69	Correct	31 ms	12952 KB	Output is correct
70	Correct	237 ms	20984 KB	Output is correct
71	Correct	792 ms	41024 KB	Output is correct
72	Correct	732 ms	40112 KB	Output is correct
73	Correct	162 ms	18868 KB	Output is correct
74	Correct	681 ms	35868 KB	Output is correct
75	Correct	75 ms	15168 KB	Output is correct
76	Correct	742 ms	40604 KB	Output is correct
77	Correct	756 ms	40948 KB	Output is correct
78	Correct	45 ms	15428 KB	Output is correct
79	Correct	523 ms	42432 KB	Output is correct
80	Correct	12 ms	12236 KB	Output is correct
81	Correct	215 ms	21040 KB	Output is correct
82	Correct	729 ms	38448 KB	Output is correct
83	Correct	676 ms	36028 KB	Output is correct
84	Correct	696 ms	35888 KB	Output is correct
85	Correct	684 ms	35956 KB	Output is correct
86	Correct	751 ms	37316 KB	Output is correct
87	Correct	765 ms	37512 KB	Output is correct

Submission #394608

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