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
++;
}
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;
}