https://pintia.cn/problem-sets/994805342720868352/problems/994805369774129152
#include<bits/stdc++.h>
using namespace std;
const int N=1e5+10;
unordered_map<int,int>ne,val,vis;
int st,n;
vector< pair<int,int> >a,b;
int main(void)
{
cin>>st>>n;
for(int i=0;i<n;i++)
{
int a,b,c; cin>>a>>b>>c;
val[a]=b,ne[a]=c;
}
while(st!=-1)
{
if(vis[abs(val[st])]) b.push_back({
st,val[st]});
else a.push_back({
st,val[st]}),vis[abs(val[st])]=1;
st=ne[st];
}
for(int i=0;i<a.size();i++)
{
if(i==a.size()-1) printf("%05d %d -1\n",a[i].first,a[i].second);
else printf("%05d %d %05d\n",a[i].first,a[i].second,a[i+1].first);
}
for(int i=0;i<b.size();i++)
{
if(i==b.size()-1) printf("%05d %d -1",b[i].first,b[i].second);
else printf("%05d %d %05d\n",b[i].first,b[i].second,b[i+1].first);
}
return 0;
}