Point in Polygon

input/code.cpp: In function 'int crossings(std::pair<long long int, long long int>, const std::vector<std::pair<long long int, long long int> >&)':
input/code.cpp:22:17: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
   22 |         if( (y1 <= y <y2) and (x-x1) * (y2 - y1) == (x2 -x1) * (y - y1)) return 2;
      |              ~~~^~~~
input/code.cpp:24:17: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
   24 |         if( (y1 <= y <y2) and (x-x1) * (y2 - y1) < (x2 -x1) * (y - y1)){
      |              ~~~^~~~

#include <iostream>
#include <vector>

using namespace std;

#define ll long long

int crossings(pair<ll,ll> point, const vector<pair<ll,ll>>& poli){
    ll x = point.first;
    ll y = point.second;
    ll n = poli.size();

    ll crossings = 0;

    for(int i=0; i<n; i++){
        ll x1 = poli[i].first;
        ll y1 = poli[i].second;

        ll x2 = poli[ (i+1) % n].first;
        ll y2 = poli[ (i+1) % n].second;

        if( (y1 <= y <y2) and (x-x1) * (y2 - y1) == (x2 -x1) * (y - y1)) return 2;

        if( (y1 <= y <y2) and (x-x1) * (y2 - y1) < (x2 -x1) * (y - y1)){
            crossings += 1;
        }

    }

    if(crossings%2==1) return 0;


    return 1;
}

int main(){

    int n,m;

    cin >> n >> m;

    vector<pair<ll,ll>> poli(n);

    for(int i=0; i<n; i++){
        ll a,b;
        cin >> a >> b;
        poli[i] = make_pair(a,b);
    }

    for(int i=0; i<m; i++){
        ll a,b;
        cin >> a >> b;
        int cross = crossings(make_pair(a,b), poli);
        if(cross==0)cout << "OUTSIDE" << endl;
        else if (cross==1)cout << "INSIDE" << endl;
        else cout << "BOUNDARY" << endl;
    }


}

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: ACCEPTED

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER