Submission #830211

#	Time	Username	Problem	Language	Result	Execution time	Memory
830211		yusuf12360	Network (BOI15_net)	C++14	Compilation error	0 ms	0 KiB

net

#include<bits/stdc++.h>
#define int long long
using namespace std;
signed main() {
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	int n; cin >> n;
	vector<vector<int>> adj(n);
	vector<pair<int, int>> leaf, ans;
	map<int, int> mp;
	for(int i=1; i<n; i++) {
		int u, v; cin >> u >> v; --u; --v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	} int cnt=0;
	for(int i=0; i<n; i++) {
		if(adj[i].size()>1) continue;
		leaf.push_back({adj[i][0], i});
		cnt++;
	}
	sort(leaf.begin(), leaf.end());
	for(int i=0; i<cnt/2; i++) 
		ans.push_back({leaf[i], leaf[i+cnt/2]});
	cout << ans.size() << '\n';
	for(auto p : ans) cout << p.first << ' ' << p.second << '\n';
	return 0;
}

Compilation message (stderr)

net.cpp: In function 'int main()':
net.cpp:22:41: error: no matching function for call to 'std::vector<std::pair<long long int, long long int> >::push_back(<brace-enclosed initializer list>)'
   22 |   ans.push_back({leaf[i], leaf[i+cnt/2]});
      |                                         ^
In file included from /usr/include/c++/10/vector:67,
                 from /usr/include/c++/10/queue:61,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:86,
                 from net.cpp:1:
/usr/include/c++/10/bits/stl_vector.h:1187:7: note: candidate: 'void std::vector<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = std::pair<long long int, long long int>; _Alloc = std::allocator<std::pair<long long int, long long int> >; std::vector<_Tp, _Alloc>::value_type = std::pair<long long int, long long int>]'
 1187 |       push_back(const value_type& __x)
      |       ^~~~~~~~~
/usr/include/c++/10/bits/stl_vector.h:1187:35: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'const value_type&' {aka 'const std::pair<long long int, long long int>&'}
 1187 |       push_back(const value_type& __x)
      |                 ~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/10/bits/stl_vector.h:1203:7: note: candidate: 'void std::vector<_Tp, _Alloc>::push_back(std::vector<_Tp, _Alloc>::value_type&&) [with _Tp = std::pair<long long int, long long int>; _Alloc = std::allocator<std::pair<long long int, long long int> >; std::vector<_Tp, _Alloc>::value_type = std::pair<long long int, long long int>]'
 1203 |       push_back(value_type&& __x)
      |       ^~~~~~~~~
/usr/include/c++/10/bits/stl_vector.h:1203:30: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'std::vector<std::pair<long long int, long long int> >::value_type&&' {aka 'std::pair<long long int, long long int>&&'}
 1203 |       push_back(value_type&& __x)
      |                 ~~~~~~~~~~~~~^~~