oj.uz

Submission #940116

# Submission time Handle Problem Language Result Execution time Memory
940116 2024-03-07T05:45:11 Z vjudge1 Network (BOI15_net) C++17
63 / 100
 5 ms 10076 KB 
// in the name of God
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define fast() ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define ff first
#define ss second
#define pb(x) push_back(x)
#define all(x) x.begin(), x.end()
#define mk make_pair
#define ppb pop_back
#define endl '\n'
#define pii pair<int, int>
#define sz(x) (int)x.size()
#define file() freopen("input.txt", "r", stdin);
#pragma GCC optimize("Ofast")
#pragma GCC optimize("O4")
#pragma GCC optimize("unroll-loops")
//#pragma GCC target("avx2")
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int mod = 1e9 + 7, maxn = 2e5 + 10, sq = 3163, inf = 1e18 + 10, lg = 25, pp = 4447, modd = 1e9 + 9;

int n;
vector<vector<int>> g(maxn);
vector<int> b;

void dfs(int u = 0, int par = -1){
	if(g[u].size() == 1) b.pb(u);
	for(int v : g[u]){
		if(v != par) dfs(v, u);
	}
}
signed main(){
	fast();//file();
	cin >> n;
	for(int i = 1; i < n; ++i){
		int u, v; cin >> u >> v;
		u--; v--;
		g[v].pb(u);
		g[u].pb(v);
	}
	dfs();
	int ans = b.size() + 1;
	ans /= 2;
	cout << ans << endl;
	for(int i = 0; i < (b.size() - (b.size() / 2)); ++i){
		cout << b[i] + 1 << " " << b[i + (b.size() / 2)] + 1 << endl;
	}
}
// Happiness can be found even in the darkest of times,
// if one only remembers to turn on the light.

Compilation message

net.cpp: In function 'int main()':
net.cpp:46:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |  for(int i = 0; i < (b.size() - (b.size() / 2)); ++i){
      |                 ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5208 KB Output is correct
2 Correct 2 ms 4952 KB Output is correct
3 Correct 2 ms 4952 KB Output is correct
4 Correct 1 ms 4956 KB Output is correct
5 Correct 1 ms 4956 KB Output is correct
6 Correct 2 ms 4952 KB Output is correct
7 Correct 2 ms 4952 KB Output is correct
8 Correct 2 ms 4956 KB Output is correct
9 Correct 2 ms 4956 KB Output is correct
10 Correct 1 ms 4956 KB Output is correct
11 Correct 2 ms 4956 KB Output is correct
12 Correct 2 ms 4956 KB Output is correct
13 Correct 2 ms 4956 KB Output is correct
14 Correct 2 ms 4956 KB Output is correct
15 Correct 2 ms 4956 KB Output is correct
16 Correct 2 ms 4956 KB Output is correct
17 Correct 2 ms 4956 KB Output is correct
18 Correct 1 ms 4956 KB Output is correct
19 Correct 2 ms 4956 KB Output is correct
20 Correct 3 ms 4956 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5208 KB Output is correct
2 Correct 2 ms 4952 KB Output is correct
3 Correct 2 ms 4952 KB Output is correct
4 Correct 1 ms 4956 KB Output is correct
5 Correct 1 ms 4956 KB Output is correct
6 Correct 2 ms 4952 KB Output is correct
7 Correct 2 ms 4952 KB Output is correct
8 Correct 2 ms 4956 KB Output is correct
9 Correct 2 ms 4956 KB Output is correct
10 Correct 1 ms 4956 KB Output is correct
11 Correct 2 ms 4956 KB Output is correct
12 Correct 2 ms 4956 KB Output is correct
13 Correct 2 ms 4956 KB Output is correct
14 Correct 2 ms 4956 KB Output is correct
15 Correct 2 ms 4956 KB Output is correct
16 Correct 2 ms 4956 KB Output is correct
17 Correct 2 ms 4956 KB Output is correct
18 Correct 1 ms 4956 KB Output is correct
19 Correct 2 ms 4956 KB Output is correct
20 Correct 3 ms 4956 KB Output is correct
21 Correct 2 ms 4952 KB Output is correct
22 Correct 2 ms 5212 KB Output is correct
23 Correct 2 ms 5212 KB Output is correct
24 Correct 2 ms 5212 KB Output is correct
25 Correct 2 ms 5212 KB Output is correct
26 Correct 2 ms 5212 KB Output is correct
27 Correct 2 ms 5208 KB Output is correct
28 Correct 2 ms 5212 KB Output is correct
29 Correct 2 ms 5212 KB Output is correct
30 Correct 1 ms 4956 KB Output is correct
31 Correct 2 ms 5212 KB Output is correct
32 Correct 1 ms 4956 KB Output is correct
33 Correct 1 ms 4956 KB Output is correct
34 Correct 1 ms 4956 KB Output is correct
35 Correct 2 ms 4956 KB Output is correct
36 Correct 2 ms 4956 KB Output is correct
37 Correct 2 ms 4952 KB Output is correct
38 Correct 2 ms 5212 KB Output is correct
39 Correct 2 ms 4956 KB Output is correct
40 Correct 2 ms 4956 KB Output is correct
41 Correct 2 ms 4956 KB Output is correct
42 Correct 1 ms 4952 KB Output is correct
43 Correct 1 ms 5208 KB Output is correct
44 Correct 2 ms 4956 KB Output is correct
45 Correct 2 ms 4956 KB Output is correct
46 Correct 2 ms 5208 KB Output is correct
47 Correct 2 ms 4956 KB Output is correct
48 Correct 1 ms 4956 KB Output is correct
49 Correct 2 ms 5212 KB Output is correct
50 Correct 2 ms 4956 KB Output is correct
51 Correct 1 ms 4956 KB Output is correct
52 Correct 2 ms 4956 KB Output is correct
53 Correct 3 ms 5208 KB Output is correct
54 Correct 2 ms 4956 KB Output is correct
55 Correct 2 ms 4952 KB Output is correct
56 Correct 2 ms 4956 KB Output is correct
57 Correct 1 ms 4956 KB Output is correct
58 Correct 2 ms 5256 KB Output is correct

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5208 KB Output is correct
2 Correct 2 ms 4952 KB Output is correct
3 Correct 2 ms 4952 KB Output is correct
4 Correct 1 ms 4956 KB Output is correct
5 Correct 1 ms 4956 KB Output is correct
6 Correct 2 ms 4952 KB Output is correct
7 Correct 2 ms 4952 KB Output is correct
8 Correct 2 ms 4956 KB Output is correct
9 Correct 2 ms 4956 KB Output is correct
10 Correct 1 ms 4956 KB Output is correct
11 Correct 2 ms 4956 KB Output is correct
12 Correct 2 ms 4956 KB Output is correct
13 Correct 2 ms 4956 KB Output is correct
14 Correct 2 ms 4956 KB Output is correct
15 Correct 2 ms 4956 KB Output is correct
16 Correct 2 ms 4956 KB Output is correct
17 Correct 2 ms 4956 KB Output is correct
18 Correct 1 ms 4956 KB Output is correct
19 Correct 2 ms 4956 KB Output is correct
20 Correct 3 ms 4956 KB Output is correct
21 Correct 2 ms 4952 KB Output is correct
22 Correct 2 ms 5212 KB Output is correct
23 Correct 2 ms 5212 KB Output is correct
24 Correct 2 ms 5212 KB Output is correct
25 Correct 2 ms 5212 KB Output is correct
26 Correct 2 ms 5212 KB Output is correct
27 Correct 2 ms 5208 KB Output is correct
28 Correct 2 ms 5212 KB Output is correct
29 Correct 2 ms 5212 KB Output is correct
30 Correct 1 ms 4956 KB Output is correct
31 Correct 2 ms 5212 KB Output is correct
32 Correct 1 ms 4956 KB Output is correct
33 Correct 1 ms 4956 KB Output is correct
34 Correct 1 ms 4956 KB Output is correct
35 Correct 2 ms 4956 KB Output is correct
36 Correct 2 ms 4956 KB Output is correct
37 Correct 2 ms 4952 KB Output is correct
38 Correct 2 ms 5212 KB Output is correct
39 Correct 2 ms 4956 KB Output is correct
40 Correct 2 ms 4956 KB Output is correct
41 Correct 2 ms 4956 KB Output is correct
42 Correct 1 ms 4952 KB Output is correct
43 Correct 1 ms 5208 KB Output is correct
44 Correct 2 ms 4956 KB Output is correct
45 Correct 2 ms 4956 KB Output is correct
46 Correct 2 ms 5208 KB Output is correct
47 Correct 2 ms 4956 KB Output is correct
48 Correct 1 ms 4956 KB Output is correct
49 Correct 2 ms 5212 KB Output is correct
50 Correct 2 ms 4956 KB Output is correct
51 Correct 1 ms 4956 KB Output is correct
52 Correct 2 ms 4956 KB Output is correct
53 Correct 3 ms 5208 KB Output is correct
54 Correct 2 ms 4956 KB Output is correct
55 Correct 2 ms 4952 KB Output is correct
56 Correct 2 ms 4956 KB Output is correct
57 Correct 1 ms 4956 KB Output is correct
58 Correct 2 ms 5256 KB Output is correct
59 Runtime error 5 ms 10076 KB Execution killed with signal 11
60 Halted 0 ms 0 KB -