Line Segment Intersection

#include <iostream>
#include <ccomplex>
#include <vector>

using namespace std;

typedef long long C;
typedef complex<C> P;
#define X real()
#define Y imag()
#define cross(a,b) (conj(a)*b).Y

bool intersection(P p1, P p2, P p3, P p4){
    if(p1 == p3 or p1 == p4 or p2 == p3 or p2 == p4)return true;

    C c1 = cross(p3-p1,p3-p2);
    C c2 = cross(p4-p1,p4-p2);

    //cout << c1 << " " << c2 << endl;
    if((c1>0 and c2<0) or (c1<0 and c2>0))return true;

    c1 = cross(p1-p3,p1-p4);
    c2 = cross(p2-p3,p2-p4);

    //cout << c1 << " " << c2 << endl;
    if((c1>0 and c2<0) or (c1<0 and c2>0))return true;


    return false;
}

int main(){
    int t;
    cin >> t;
    for(int i=0; i< t; i++){
        vector<P> vec(4);
        
        for(int l=0; l<4; l++){
            C a,b;
            cin >> a >> b;
            vec[l] = {a,b};
        }

        if(intersection(vec[0], vec[1], vec[2], vec[3])){
            cout << "YES" << endl;
        }
        else cout << "NO" << endl;


    }
}

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: ACCEPTED