卡常96分，最后一个点差0.10s

#include<bits/stdc++.h>
using namespace std;
const int po=1e4-1;
unordered_map<long long,int> mp;
unordered_map<long long,vector<int> > op;
int n,m,ans=0,uu[50004],vv[50004],ww[50004];
long long hsh(int u,int v,int w)
{
	return 1LL*u*po*po+v*po+w;
}
void work1(int a,int b,int c)
{
	for(int d:op[hsh(0,a,b)])
	{
	    if(d<=c)continue;
		if(mp[hsh(a,c,d)]==1&&mp[hsh(b,c,d)]==1&&mp[hsh(a,b,d)]==1)
		ans++;
	}
}
signed main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
    cin>>n>>m;
    n=m;
    int i=0;
    while(m--)
    {
        i++;
		cin>>uu[i]>>vv[i]>>ww[i];
		mp[hsh(uu[i],vv[i],ww[i])]=1;
		op[hsh(0,uu[i],vv[i])].push_back(ww[i]);
	}
	i=0;
	while(n--)
	{
	    i++;
	    work1(uu[i],vv[i],ww[i]);
	}
	cout<<ans;
	return 0;
}