oj.uz

Submission #397020

# Submission time Handle Problem Language Result Execution time Memory
397020 2021-05-01T06:53:59 Z The_Blitz Network (BOI15_net) C++17
100 / 100
 727 ms 47668 KB 
// Restart
// += O(logn) ; + = O(n)
 
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp> // Common file
#include <ext/pb_ds/tree_policy.hpp> // Including tree_order_statistics_node_update
 
#define fastio ios_base::sync_with_stdio(0);cin.tie(0)
#define fst first
#define snd second
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define sz size()
#define FORN(i,j,n) for(int i=j; i<(int)n;i++) 
#define FOR(i,n) FORN(i,0,n)
#define FORIT(i,x) for( auto i = x.begin() ; i != x.end() ; i++ )
#define MOD 998244353LL
#define MOD1 1000000007LL
#define LIM 262150
#define ones(x) __builtin_popcount(x)
#define trace(x)    cerr << #x << ": " << x << endl;
#define trace2(x, y) cerr << #x << ": " << x << " | " << #y << ": " << y << endl;
#define trace3(x, y,z) cerr << #x << ": " << x << " | " << #y << ": " << y << " | " << #z << ": " << z << endl;
#define INF 1000000000
#define in(x)  cin>>x;
#define out(x) cout<<x;
#define MAXIMO 1LL<<60

#define loga2(x) __builtin_ctzll(x)
//SOLO PARA POTENCIAS DE 2
 
using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll ;
typedef unsigned long long ull ;
typedef vector <int> vi;
typedef pair <int,int> ii;
typedef pair <int,ii> iii;
typedef vector <string> vs;
typedef vector <ii> vii;
typedef vector <iii> viii;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;


vi G[500005];
vi ans;

void dfs(int curr, int ant = -1){
	bool leaf = true;
	for(auto v: G[curr]) {
		if(ant != v){
			dfs(v,curr);
			leaf=false;
		}
	}
	if(leaf) ans.pb(curr);
}

void go(){

	int n; cin>>n;
	
	for(int i=1; i<n;i++){
		int x, y; cin >> x >> y;
		G[x].pb(y);
		G[y].pb(x);
	}
	//Input is a tree
	for(int i=1; i<=n; i++){
		if(G[i].size() != 1){
			dfs(i);
			break;
		}
	}

	cout<< (ans.size() + 1)/2 <<"\n";


	for(int i=0; i< (ans.size()+1)/2; i++){
		cout<<ans[i] << " " << ans[i + ans.size()/2 ]<<"\n";
	}

}


void timer(){
	clock_t begin = clock();
	go();
	clock_t end = clock();
	double time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
	cout<<time_spent<<"\n";
}	

 
int main() {
  //fastio;
  go();
  //timer();
  return 0;
}

Compilation message

net.cpp: In function 'void go()':
net.cpp:83:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   83 |  for(int i=0; i< (ans.size()+1)/2; i++){
      |               ~^~~~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 11980 KB Output is correct
2 Correct 7 ms 12048 KB Output is correct
3 Correct 9 ms 11980 KB Output is correct
4 Correct 9 ms 11980 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Correct 8 ms 11980 KB Output is correct
7 Correct 8 ms 11980 KB Output is correct
8 Correct 7 ms 11980 KB Output is correct
9 Correct 8 ms 12040 KB Output is correct
10 Correct 7 ms 11980 KB Output is correct
11 Correct 7 ms 12024 KB Output is correct
12 Correct 7 ms 11980 KB Output is correct
13 Correct 9 ms 12040 KB Output is correct
14 Correct 9 ms 12040 KB Output is correct
15 Correct 8 ms 11980 KB Output is correct
16 Correct 8 ms 11972 KB Output is correct
17 Correct 7 ms 11980 KB Output is correct
18 Correct 8 ms 11980 KB Output is correct
19 Correct 8 ms 12040 KB Output is correct
20 Correct 7 ms 11980 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 11980 KB Output is correct
2 Correct 7 ms 12048 KB Output is correct
3 Correct 9 ms 11980 KB Output is correct
4 Correct 9 ms 11980 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Correct 8 ms 11980 KB Output is correct
7 Correct 8 ms 11980 KB Output is correct
8 Correct 7 ms 11980 KB Output is correct
9 Correct 8 ms 12040 KB Output is correct
10 Correct 7 ms 11980 KB Output is correct
11 Correct 7 ms 12024 KB Output is correct
12 Correct 7 ms 11980 KB Output is correct
13 Correct 9 ms 12040 KB Output is correct
14 Correct 9 ms 12040 KB Output is correct
15 Correct 8 ms 11980 KB Output is correct
16 Correct 8 ms 11972 KB Output is correct
17 Correct 7 ms 11980 KB Output is correct
18 Correct 8 ms 11980 KB Output is correct
19 Correct 8 ms 12040 KB Output is correct
20 Correct 7 ms 11980 KB Output is correct
21 Correct 9 ms 12156 KB Output is correct
22 Correct 9 ms 12064 KB Output is correct
23 Correct 10 ms 12060 KB Output is correct
24 Correct 11 ms 12108 KB Output is correct
25 Correct 9 ms 12056 KB Output is correct
26 Correct 8 ms 12108 KB Output is correct
27 Correct 10 ms 12112 KB Output is correct
28 Correct 9 ms 12108 KB Output is correct
29 Correct 9 ms 12052 KB Output is correct
30 Correct 7 ms 11980 KB Output is correct
31 Correct 9 ms 12108 KB Output is correct
32 Correct 7 ms 11932 KB Output is correct
33 Correct 7 ms 11980 KB Output is correct
34 Correct 8 ms 11980 KB Output is correct
35 Correct 8 ms 11980 KB Output is correct
36 Correct 8 ms 12036 KB Output is correct
37 Correct 8 ms 11980 KB Output is correct
38 Correct 8 ms 12048 KB Output is correct
39 Correct 8 ms 11980 KB Output is correct
40 Correct 8 ms 11980 KB Output is correct
41 Correct 8 ms 11980 KB Output is correct
42 Correct 8 ms 12068 KB Output is correct
43 Correct 9 ms 11980 KB Output is correct
44 Correct 9 ms 11984 KB Output is correct
45 Correct 8 ms 11980 KB Output is correct
46 Correct 8 ms 11980 KB Output is correct
47 Correct 9 ms 11980 KB Output is correct
48 Correct 8 ms 11984 KB Output is correct
49 Correct 9 ms 11980 KB Output is correct
50 Correct 8 ms 11980 KB Output is correct
51 Correct 8 ms 11980 KB Output is correct
52 Correct 8 ms 11984 KB Output is correct
53 Correct 8 ms 11980 KB Output is correct
54 Correct 8 ms 11980 KB Output is correct
55 Correct 9 ms 12060 KB Output is correct
56 Correct 9 ms 12040 KB Output is correct
57 Correct 9 ms 12008 KB Output is correct
58 Correct 9 ms 12052 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 11980 KB Output is correct
2 Correct 7 ms 12048 KB Output is correct
3 Correct 9 ms 11980 KB Output is correct
4 Correct 9 ms 11980 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Correct 8 ms 11980 KB Output is correct
7 Correct 8 ms 11980 KB Output is correct
8 Correct 7 ms 11980 KB Output is correct
9 Correct 8 ms 12040 KB Output is correct
10 Correct 7 ms 11980 KB Output is correct
11 Correct 7 ms 12024 KB Output is correct
12 Correct 7 ms 11980 KB Output is correct
13 Correct 9 ms 12040 KB Output is correct
14 Correct 9 ms 12040 KB Output is correct
15 Correct 8 ms 11980 KB Output is correct
16 Correct 8 ms 11972 KB Output is correct
17 Correct 7 ms 11980 KB Output is correct
18 Correct 8 ms 11980 KB Output is correct
19 Correct 8 ms 12040 KB Output is correct
20 Correct 7 ms 11980 KB Output is correct
21 Correct 9 ms 12156 KB Output is correct
22 Correct 9 ms 12064 KB Output is correct
23 Correct 10 ms 12060 KB Output is correct
24 Correct 11 ms 12108 KB Output is correct
25 Correct 9 ms 12056 KB Output is correct
26 Correct 8 ms 12108 KB Output is correct
27 Correct 10 ms 12112 KB Output is correct
28 Correct 9 ms 12108 KB Output is correct
29 Correct 9 ms 12052 KB Output is correct
30 Correct 7 ms 11980 KB Output is correct
31 Correct 9 ms 12108 KB Output is correct
32 Correct 7 ms 11932 KB Output is correct
33 Correct 7 ms 11980 KB Output is correct
34 Correct 8 ms 11980 KB Output is correct
35 Correct 8 ms 11980 KB Output is correct
36 Correct 8 ms 12036 KB Output is correct
37 Correct 8 ms 11980 KB Output is correct
38 Correct 8 ms 12048 KB Output is correct
39 Correct 8 ms 11980 KB Output is correct
40 Correct 8 ms 11980 KB Output is correct
41 Correct 8 ms 11980 KB Output is correct
42 Correct 8 ms 12068 KB Output is correct
43 Correct 9 ms 11980 KB Output is correct
44 Correct 9 ms 11984 KB Output is correct
45 Correct 8 ms 11980 KB Output is correct
46 Correct 8 ms 11980 KB Output is correct
47 Correct 9 ms 11980 KB Output is correct
48 Correct 8 ms 11984 KB Output is correct
49 Correct 9 ms 11980 KB Output is correct
50 Correct 8 ms 11980 KB Output is correct
51 Correct 8 ms 11980 KB Output is correct
52 Correct 8 ms 11984 KB Output is correct
53 Correct 8 ms 11980 KB Output is correct
54 Correct 8 ms 11980 KB Output is correct
55 Correct 9 ms 12060 KB Output is correct
56 Correct 9 ms 12040 KB Output is correct
57 Correct 9 ms 12008 KB Output is correct
58 Correct 9 ms 12052 KB Output is correct
59 Correct 563 ms 36036 KB Output is correct
60 Correct 674 ms 38724 KB Output is correct
61 Correct 7 ms 12032 KB Output is correct
62 Correct 8 ms 11980 KB Output is correct
63 Correct 501 ms 33672 KB Output is correct
64 Correct 11 ms 12364 KB Output is correct
65 Correct 27 ms 13832 KB Output is correct
66 Correct 220 ms 27876 KB Output is correct
67 Correct 700 ms 46772 KB Output is correct
68 Correct 688 ms 47668 KB Output is correct
69 Correct 19 ms 12860 KB Output is correct
70 Correct 183 ms 21300 KB Output is correct
71 Correct 563 ms 41832 KB Output is correct
72 Correct 543 ms 40660 KB Output is correct
73 Correct 153 ms 18984 KB Output is correct
74 Correct 659 ms 37668 KB Output is correct
75 Correct 55 ms 15168 KB Output is correct
76 Correct 550 ms 41712 KB Output is correct
77 Correct 521 ms 41592 KB Output is correct
78 Correct 54 ms 15408 KB Output is correct
79 Correct 727 ms 45132 KB Output is correct
80 Correct 10 ms 12236 KB Output is correct
81 Correct 170 ms 21172 KB Output is correct
82 Correct 601 ms 39536 KB Output is correct
83 Correct 650 ms 37732 KB Output is correct
84 Correct 664 ms 37616 KB Output is correct
85 Correct 720 ms 37720 KB Output is correct
86 Correct 680 ms 38740 KB Output is correct
87 Correct 663 ms 39024 KB Output is correct