Submission #277494

#	Time	Username	Problem	Language	Result	Execution time	Memory
277494		Fidisk	Network (BOI15_net)	C++14	0 / 100	1 ms	384 KiB

net

#include <bits/stdc++.h>
using namespace std;
 
#define oo 1e9
#define fi first
#define se second
#define sp(iiii) setprecision(iiii)
#define IO ios_base::sync_with_stdio(false); cin.tie(0)
#define ms(aaaa,xxxx) memset(aaaa,xxxx,sizeof(aaaa))
#define cntbit(xxxx) __builtin_popcount(xxxx)
#define getbit(xxxx,aaaa) ((xxxx>>(aaaa-1))&1)
#define _cos(xxxx) cos(xxxx*acos(-1)/180)
#define _sin(xxxx) sin(xxxx*acos(-1)/180)
#define _tan(xxxx) tan(xxxx*acos(-1)/180)
#define PE cout<<fixed
 
typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<pair<int,int>,int> piii;
typedef pair<long long,long long> pll;
typedef pair<pair<long long,long long>,long long> plll;
 
const ld pi=acos(-1);

int u,v,i,deg[500009],n;
vector<int> ans;

int main() {
    cin>>n;
    for (i=1;i<n;i++) {
        cin>>u>>v;
        deg[u]++;
        deg[v]++;
    }
    for (i=1;i<=n;i++) {
        if (deg[i]==1) {
            ans.push_back(i);
        }
    }
    cout<<(ans.size()+1)/2<<'\n';
    for (i=0;i<ans.size()/2;i++) {
        cout<<ans[i*2]<<' '<<ans[i*2+1]<<'\n';
    }
    if (ans.size()%2!=0) {
        cout<<ans[ans.size()-1]<<' '<<(ans[ans.size()-1]==1?2:1)<<'\n';
    }
}
    

Compilation message (stderr)

net.cpp: In function 'int main()':
net.cpp:43:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |     for (i=0;i<ans.size()/2;i++) {
      |              ~^~~~~~~~~~~~~

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