demgocvuong.cpp

#include<iostream>
#include<cstdlib>
#include<vector>

#define long long long
#define nln '\n'

using namespace std;

bool right_angle(pair<long, long> A, pair<long, long> B, pair<long, long> C)
{
    pair<long, long> vta({B.first-A.first, B.second-A.second});
    pair<long, long> vtb({C.first-B.first, C.second-B.second});
    return (vta.first*vtb.first + vta.second*vtb.second == 0);
}

int main()
{
    cin.tie(0)->sync_with_stdio(0);
    cout.tie(0)->sync_with_stdio(0);
    //freopen("demgocvuong.inp", "r", stdin);
    long T;
    cin >> T;
    while (T--){
        vector<pair<long, long>> pnt(4);
        for (long i = 0; i < 4; ++i)
            cin >> pnt[i].first >> pnt[i].second;
        pnt.push_back({pnt[0].first, pnt[0].second});
        pnt.push_back({pnt[1].first, pnt[1].second});
        long ans = 0;
        for (long i = 1; i <= 4; ++i)
            if (right_angle(pnt[i-1], pnt[i], pnt[i+1]))
                ++ans;
        cout << ans << nln;
    }
    return 0;
}