Broken car race

input/code.cpp: In function 'std::vector<std::complex<double> > convex_hull(std::vector<std::complex<double> >&)':
input/code.cpp:40:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::complex<double> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |     for (auto i = 0; i < points.size(); i++) {
      |                      ~~^~~~~~~~~~~~~~~
input/code.cpp: In function 'int main()':
input/code.cpp:92:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::complex<double> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   92 |     for (int i = 0; i < dnhull.size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~
input/code.cpp:99:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::complex<double> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   99 |         for (int i = 1; i < uphull.size() - 1; i++) {...

#include <bits/stdc++.h>
#include <complex.h>
using namespace std;

#define all(arr) begin(arr), end(arr)

typedef complex<double> P;

const long long mod = pow(10, 9) + 7;

#define PI 3.141

long long fact(long long i) {
    long long n = i;
    while(i--) n *= i;
    return n;
}

int nxt() {
    int n;
    cin >> n;
    return n;
}

bool comp(P a, P b) {
    if (a.real() < b.real()) {
        return true;
    }else if (a.real() == b.real()) {
        return a.imag() < b.imag();
    }
    return false;
}

double angle(P a, P b) {
    return arg(b) - arg(a);
}

vector<P> convex_hull(vector<P>& points) {
    vector<P> hull;
    for (auto i = 0; i < points.size(); i++) {
        hull.push_back(points[i]);
        if (hull.size() > 2) {
            auto v0 = hull.end() - 3;
            auto v1 = hull.end() - 2;
            auto v2 = hull.end() - 1;

            auto a = *v2 - *v1;
            auto b = *v0 - *v1;
            auto c = angle(a, b);
            if (c < 0 || c > numbers::pi) {
                hull.erase(v1);
            }
        }
    }
    return hull;
}

int main () {
    //freopen("input.txt", "r", stdin);

    int n = nxt();
    vector<P> points;

    for (int i = 0; i< n; i++) {
        double x, y;
        cin >> x >> y;
        points.push_back({x, y});
    }

    sort(all(points), comp);
    auto dnhull = convex_hull(points);

    if (dnhull.size() >= 4) {
        for (int i = 0; i < 4; i++) {
            auto pt = dnhull[i];
            cout << pt.real() << " " << pt.imag() << "\n";
        }
        return 0;
    }

    sort(points.rbegin(), points.rend(), comp);
    auto uphull = convex_hull(points);

    if (dnhull.size() + uphull.size() - 2 >= 4) {
        cout << "YES" << "\n";
    } else {
        cout << "NO" << "\n";
        return 0;
    }

    int count = 0;
    for (int i = 0; i < dnhull.size(); i++) {
        auto pt = dnhull[i];
        cout << pt.real() << " " << pt.imag() << "\n";
        count++;
    }

    if (uphull.size() > 1) {
        for (int i = 1; i < uphull.size() - 1; i++) {
            if (count == 4) {
                return 0;
            }
            auto pt = uphull[i];
            cout << pt.real() << " " << pt.imag() << "\n";
            count++;
        }
    }

    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

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

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: WRONG ANSWER

Test 17

Verdict: WRONG ANSWER

Test 18

Verdict: WRONG ANSWER

Test 19

Verdict: WRONG ANSWER

Test 20

Verdict: WRONG ANSWER

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: WRONG ANSWER

Test 24

Verdict: WRONG ANSWER

Test 25

Verdict: WRONG ANSWER

Test 26

Verdict: WRONG ANSWER

Test 27

Verdict: WRONG ANSWER

Test 28

Verdict: WRONG ANSWER