test/yosupo/geometry/sort_points_by_argument.test.cpp

// competitive-verifier: PROBLEM https://judge.yosupo.jp/problem/sort_points_by_argument
#include <algorithm>
#include <cmath>
#include <iostream>
#include <tuple>
#include <vector>

int main(void) {
    int n;
    std::cin >> n;
    std::vector<std::tuple<int, int, long double>> v;
    for (int i = 0; i < n; ++i) {
        int x, y;
        std::cin >> x >> y;
        v.emplace_back(x, y, std::atan2((long double)y, x));
    }
    std::sort(v.begin(), v.end(), [&](auto x, auto y) { return std::get<2>(x) < std::get<2>(y); });
    for (auto &&[x, y, z] : v) std::cout << x << ' ' << y << '\n';

    return 0;
}

bundled

#line 1 "test/yosupo/geometry/sort_points_by_argument.test.cpp"
// competitive-verifier: PROBLEM https://judge.yosupo.jp/problem/sort_points_by_argument
#include <algorithm>
#include <cmath>
#include <iostream>
#include <tuple>
#include <vector>

int main(void) {
    int n;
    std::cin >> n;
    std::vector<std::tuple<int, int, long double>> v;
    for (int i = 0; i < n; ++i) {
        int x, y;
        std::cin >> x >> y;
        v.emplace_back(x, y, std::atan2((long double)y, x));
    }
    std::sort(v.begin(), v.end(), [&](auto x, auto y) { return std::get<2>(x) < std::get<2>(y); });
    for (auto &&[x, y, z] : v) std::cout << x << ' ' << y << '\n';

    return 0;
}