New Year Snowmen CodeForces - 140C

#include<iostream> #include<cstdio> #include<map> #include<set> #include<vector> #include<algorithm> using namespace std; map<int,int>mapp; typedef pair<int,int>pii; set<pii>seet; vector<int >vec; int main() { int t,n; cin>>t; for(int i=0;i<t;i++) { scanf("%d",&n); mapp[n]++; } map<int ,int>::iterator it=mapp.begin(); for(;it!=mapp.end();it++) seet.insert(pii(it->second,it->first)); while(seet.size()>=3) { pii ans[3]; for(int i=0;i<3;i++) { ans[i]=*--seet.end(); seet.erase(--seet.end()); vec.push_back(ans[i].second); } for(int i=0;i<3;i++) if(--ans[i].first>0) seet.insert(ans[i]); sort(vec.rbegin(),vec.rbegin()+3); } cout<<vec.size()/3<<endl; for(int i=0; i<vec.size(); i+=3) printf("%d %d %d\n",vec[i],vec[i+1],vec[i+2]); return 0; }