int main(){
    vector<int> test1 {0};
    vector<int> test2 {-1, 3, 2, 4,-10, 100};
    QuickSort solver;
    solver.qsort(test1);
    solver.qsort(test2);
    assert(solver.isSorted(0, test1.size()-1, test1));
    assert(solver.isSorted(0, test2.size()-1, test2));
}