답안 #940077

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
940077	2024-03-07T05:11:56 Z	Baizho	Network (BOI15_net)	C++14	100 / 100	381 ms	42448 KB

#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
  
#define ordered_set tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update>
 
 #pragma GCC optimize("Ofast,unroll-loops,fast-math")
 #pragma GCC target("popcnt,avx2")
 
 
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll,ll> pll;
 
#define sz size()
#define ff first
#define ss second
#define all(a) a.begin(),a.end()
#define pb push_back
 
const int mod = ll(1e9)+7; //(b + (a%b)) % b (to mod -1%(10^9+7) correctly in c++ its -1 but its suppose to be 10^9+6
const ll MOD = 998244353;  // (a%mod)*(binpow(b,mod-2,mod) = (a/b)%mod
const int N = ll(5e5)+100;
const int M = ll(2e5) + 100;
const long long inf = 2e18;
//const long double eps = 1e-15L;
 
ll lcm(ll a, ll b) { return (a / __gcd(a,b))*b; }
 
ll binpow(ll a, ll b, ll m) { ll res=1; a %= m; while(b>0){ if(b&1)res=(res * a) % m; a=(a * a) % m; b/=2; } return res%m;}
 
void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }

int n;
vector<int> g[N];
vector<int> leaf;

void dfs(int v, int p = 0) {
	if(g[v].size() == 1) leaf.pb(v);
	for(auto to : g[v]) {
		if(to == p) continue;
		dfs(to, v);
	}
}

void Baizho() {
	cin>>n;
	for(int i = 1; i <= n - 1; i ++) {
		int a, b; cin>>a>>b;
		g[a].pb(b);
		g[b].pb(a);
	}
	dfs(1);
	int m = leaf.size();
	cout<<(m + 1) / 2<<"\n";
	for(int i = 0; i < (m + 1) / 2; i ++) {
		cout<<leaf[i]<<" "<<leaf[i + m / 2]<<"\n";
	}
}
 
signed main() {		
// 	Freopen("nondec");
    ios_base::sync_with_stdio(false);   
    cin.tie(0);cout.tie(0); 
//   	precalc();
   	
    int ttt = 1;
//    cin>>ttt;
 
    for(int i=1; i<=ttt; i++) {Baizho(); }
}

Compilation message

net.cpp: In function 'void Freopen(std::string)':
net.cpp:35:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 | void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }
      |                           ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
net.cpp:35:76: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 | void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }
      |                                                                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

#	결과	실행 시간	메모리	Grader output
1	Correct	3 ms	12124 KB	Output is correct
2	Correct	3 ms	12124 KB	Output is correct
3	Correct	3 ms	12120 KB	Output is correct
4	Correct	3 ms	12124 KB	Output is correct
5	Correct	3 ms	12124 KB	Output is correct
6	Correct	3 ms	12120 KB	Output is correct
7	Correct	4 ms	12124 KB	Output is correct
8	Correct	4 ms	12124 KB	Output is correct
9	Correct	3 ms	12124 KB	Output is correct
10	Correct	3 ms	12124 KB	Output is correct
11	Correct	3 ms	12124 KB	Output is correct
12	Correct	3 ms	12196 KB	Output is correct
13	Correct	4 ms	12124 KB	Output is correct
14	Correct	4 ms	12120 KB	Output is correct
15	Correct	3 ms	12124 KB	Output is correct
16	Correct	4 ms	12120 KB	Output is correct
17	Correct	4 ms	12124 KB	Output is correct
18	Correct	3 ms	12124 KB	Output is correct
19	Correct	3 ms	12132 KB	Output is correct
20	Correct	3 ms	12196 KB	Output is correct

Subtask #2
45.0 / 45.0

#	결과	실행 시간	메모리	Grader output
1	Correct	3 ms	12124 KB	Output is correct
2	Correct	3 ms	12124 KB	Output is correct
3	Correct	3 ms	12120 KB	Output is correct
4	Correct	3 ms	12124 KB	Output is correct
5	Correct	3 ms	12124 KB	Output is correct
6	Correct	3 ms	12120 KB	Output is correct
7	Correct	4 ms	12124 KB	Output is correct
8	Correct	4 ms	12124 KB	Output is correct
9	Correct	3 ms	12124 KB	Output is correct
10	Correct	3 ms	12124 KB	Output is correct
11	Correct	3 ms	12124 KB	Output is correct
12	Correct	3 ms	12196 KB	Output is correct
13	Correct	4 ms	12124 KB	Output is correct
14	Correct	4 ms	12120 KB	Output is correct
15	Correct	3 ms	12124 KB	Output is correct
16	Correct	4 ms	12120 KB	Output is correct
17	Correct	4 ms	12124 KB	Output is correct
18	Correct	3 ms	12124 KB	Output is correct
19	Correct	3 ms	12132 KB	Output is correct
20	Correct	3 ms	12196 KB	Output is correct
21	Correct	3 ms	12124 KB	Output is correct
22	Correct	6 ms	12120 KB	Output is correct
23	Correct	4 ms	12124 KB	Output is correct
24	Correct	5 ms	12124 KB	Output is correct
25	Correct	5 ms	12124 KB	Output is correct
26	Correct	4 ms	12124 KB	Output is correct
27	Correct	4 ms	12124 KB	Output is correct
28	Correct	4 ms	12120 KB	Output is correct
29	Correct	4 ms	12128 KB	Output is correct
30	Correct	4 ms	12124 KB	Output is correct
31	Correct	4 ms	12132 KB	Output is correct
32	Correct	4 ms	12144 KB	Output is correct
33	Correct	5 ms	12200 KB	Output is correct
34	Correct	4 ms	12124 KB	Output is correct
35	Correct	4 ms	12204 KB	Output is correct
36	Correct	3 ms	12124 KB	Output is correct
37	Correct	4 ms	12212 KB	Output is correct
38	Correct	4 ms	12208 KB	Output is correct
39	Correct	3 ms	12124 KB	Output is correct
40	Correct	4 ms	12200 KB	Output is correct
41	Correct	5 ms	12124 KB	Output is correct
42	Correct	5 ms	12196 KB	Output is correct
43	Correct	3 ms	12128 KB	Output is correct
44	Correct	5 ms	12132 KB	Output is correct
45	Correct	3 ms	12128 KB	Output is correct
46	Correct	4 ms	12128 KB	Output is correct
47	Correct	3 ms	12124 KB	Output is correct
48	Correct	4 ms	12132 KB	Output is correct
49	Correct	5 ms	12132 KB	Output is correct
50	Correct	3 ms	12200 KB	Output is correct
51	Correct	3 ms	12376 KB	Output is correct
52	Correct	3 ms	12124 KB	Output is correct
53	Correct	5 ms	12356 KB	Output is correct
54	Correct	3 ms	12124 KB	Output is correct
55	Correct	3 ms	12124 KB	Output is correct
56	Correct	3 ms	12124 KB	Output is correct
57	Correct	3 ms	12124 KB	Output is correct
58	Correct	4 ms	12124 KB	Output is correct

Subtask #3
37.0 / 37.0

#	결과	실행 시간	메모리	Grader output
1	Correct	3 ms	12124 KB	Output is correct
2	Correct	3 ms	12124 KB	Output is correct
3	Correct	3 ms	12120 KB	Output is correct
4	Correct	3 ms	12124 KB	Output is correct
5	Correct	3 ms	12124 KB	Output is correct
6	Correct	3 ms	12120 KB	Output is correct
7	Correct	4 ms	12124 KB	Output is correct
8	Correct	4 ms	12124 KB	Output is correct
9	Correct	3 ms	12124 KB	Output is correct
10	Correct	3 ms	12124 KB	Output is correct
11	Correct	3 ms	12124 KB	Output is correct
12	Correct	3 ms	12196 KB	Output is correct
13	Correct	4 ms	12124 KB	Output is correct
14	Correct	4 ms	12120 KB	Output is correct
15	Correct	3 ms	12124 KB	Output is correct
16	Correct	4 ms	12120 KB	Output is correct
17	Correct	4 ms	12124 KB	Output is correct
18	Correct	3 ms	12124 KB	Output is correct
19	Correct	3 ms	12132 KB	Output is correct
20	Correct	3 ms	12196 KB	Output is correct
21	Correct	3 ms	12124 KB	Output is correct
22	Correct	6 ms	12120 KB	Output is correct
23	Correct	4 ms	12124 KB	Output is correct
24	Correct	5 ms	12124 KB	Output is correct
25	Correct	5 ms	12124 KB	Output is correct
26	Correct	4 ms	12124 KB	Output is correct
27	Correct	4 ms	12124 KB	Output is correct
28	Correct	4 ms	12120 KB	Output is correct
29	Correct	4 ms	12128 KB	Output is correct
30	Correct	4 ms	12124 KB	Output is correct
31	Correct	4 ms	12132 KB	Output is correct
32	Correct	4 ms	12144 KB	Output is correct
33	Correct	5 ms	12200 KB	Output is correct
34	Correct	4 ms	12124 KB	Output is correct
35	Correct	4 ms	12204 KB	Output is correct
36	Correct	3 ms	12124 KB	Output is correct
37	Correct	4 ms	12212 KB	Output is correct
38	Correct	4 ms	12208 KB	Output is correct
39	Correct	3 ms	12124 KB	Output is correct
40	Correct	4 ms	12200 KB	Output is correct
41	Correct	5 ms	12124 KB	Output is correct
42	Correct	5 ms	12196 KB	Output is correct
43	Correct	3 ms	12128 KB	Output is correct
44	Correct	5 ms	12132 KB	Output is correct
45	Correct	3 ms	12128 KB	Output is correct
46	Correct	4 ms	12128 KB	Output is correct
47	Correct	3 ms	12124 KB	Output is correct
48	Correct	4 ms	12132 KB	Output is correct
49	Correct	5 ms	12132 KB	Output is correct
50	Correct	3 ms	12200 KB	Output is correct
51	Correct	3 ms	12376 KB	Output is correct
52	Correct	3 ms	12124 KB	Output is correct
53	Correct	5 ms	12356 KB	Output is correct
54	Correct	3 ms	12124 KB	Output is correct
55	Correct	3 ms	12124 KB	Output is correct
56	Correct	3 ms	12124 KB	Output is correct
57	Correct	3 ms	12124 KB	Output is correct
58	Correct	4 ms	12124 KB	Output is correct
59	Correct	259 ms	35448 KB	Output is correct
60	Correct	266 ms	37832 KB	Output is correct
61	Correct	4 ms	12124 KB	Output is correct
62	Correct	3 ms	12124 KB	Output is correct
63	Correct	216 ms	33268 KB	Output is correct
64	Correct	5 ms	12380 KB	Output is correct
65	Correct	10 ms	13656 KB	Output is correct
66	Correct	67 ms	25156 KB	Output is correct
67	Correct	324 ms	41852 KB	Output is correct
68	Correct	349 ms	42448 KB	Output is correct
69	Correct	7 ms	12888 KB	Output is correct
70	Correct	67 ms	21316 KB	Output is correct
71	Correct	206 ms	41020 KB	Output is correct
72	Correct	190 ms	39908 KB	Output is correct
73	Correct	54 ms	19140 KB	Output is correct
74	Correct	256 ms	36800 KB	Output is correct
75	Correct	26 ms	15324 KB	Output is correct
76	Correct	257 ms	40724 KB	Output is correct
77	Correct	171 ms	40876 KB	Output is correct
78	Correct	20 ms	15196 KB	Output is correct
79	Correct	352 ms	40660 KB	Output is correct
80	Correct	6 ms	12380 KB	Output is correct
81	Correct	72 ms	21376 KB	Output is correct
82	Correct	268 ms	38872 KB	Output is correct
83	Correct	335 ms	37036 KB	Output is correct
84	Correct	316 ms	36804 KB	Output is correct
85	Correct	332 ms	36588 KB	Output is correct
86	Correct	350 ms	37752 KB	Output is correct
87	Correct	381 ms	37712 KB	Output is correct

답안 #940077

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