Submission #764879

#	Time	Username	Problem	Language	Result	Execution time	Memory
764879		vjudge1	Network (BOI15_net)	C++17	0 / 100	2 ms	2656 KiB

net

#pragma GCC optimize("Ofast")
#pragma GCC target("avx","avx2","fma")
#pragma GCC Optimization("unroll-loops")
#pragma ("reroll")
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int maxn=1e5+9;
const long long inf=1e15;
const int mod=1e9+7;
vector<int>g[maxn];
bool used[maxn];
int in[maxn];
int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	// #ifndef ONLINE_JUDGE
       // freopen("input.txt","r",stdin);
       // freopen("output.txt","w",stdout);
       // #endif
       // 24.06.2023
       // Iseque
       int n;
       cin>>n;
       for(int i=1;i<n;i++){
              int u,v;
              cin>>u>>v;
              g[u].push_back(v);
              in[v]++;
              g[v].push_back(u);
              in[u]++;
       }
       int cnt=0;
       vector<pair<int,int>>v;
       for(int i=1;i<=n;i++){
              for(int j=1;j<=n;j++){
                     if(in[i]==1&&g[j].size()==1&&g[j][1]!=i&&i!=j) {
                            cnt++;
                            v.push_back({i,j});
                            g[j].push_back(i);
                            g[i].push_back(j);
                            in[i]++;
                            in[j]++;
                     }
              }
       }
       cout<<cnt<<'\n';
       for(int i=0;i<v.size();i++){
              cout<<v[i].first<<' '<<v[i].second<<'\n';
       }
       return 0;
}

Compilation message (stderr)

net.cpp:3: warning: ignoring '#pragma GCC Optimization' [-Wunknown-pragmas]
    3 | #pragma GCC Optimization("unroll-loops")
      | 
net.cpp:4: warning: ignoring '#pragma ( ' [-Wunknown-pragmas]
    4 | #pragma ("reroll")
      | 
net.cpp: In function 'int main()':
net.cpp:49:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |        for(int i=0;i<v.size();i++){
      |                    ~^~~~~~~~~

• Subtask 1: 0 / 18
• Subtask 2: 0 / 45
• Subtask 3: 0 / 37