};
struct MyStruct {
    int a;
    int b;

    MyStruct(int _a, int _b) : a(_a), b(_b) {}
};

int main() {
    std::vector<MyStruct> vec;
    vec.emplace_back(1,4);
    vec.emplace_back(2,3);
    vec.emplace_back(3,2);
    vec.emplace_back(4,1);

    std::sort(vec.begin(), vec.end(), [](MyStruct s1, MyStruct s2){ return s1.a > s2.a; });

    for (auto v: vec) {
        std::cout << v.a << " " << v.b << std::endl;
    }
    return 0;
}