Compilare: main.cpp: In function 'void del(std::vector<int>&, int, std::vector<int>&)': main.cpp:47:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 47 | for(int i = pos; i < heap.size(); i = i*2){ | ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:78:32: warning: passing NULL to non-pointer argument 2 of 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>::size_type, const value_type&, const allocator_type&) [with _Tp = int; _Alloc = std::allocator<int>; std::vector<_Tp, _Alloc>::size_type = long unsigned int; std::vector<_Tp, _Alloc>::value_type = int; std::vector<_Tp, _Alloc>::allocator_type = std::allocator<int>]' [-Wconversion-null] 78 | std::vector<int> ord(n,NULL); | ^ In file included from /usr/include/c++/10/vector:67, from main.cpp:3: /usr/include/c++/10/bits/stl_vector.h:522:47: note: declared here 522 | vector(size_type __n, const value_type& __value, | ~~~~~~~~~~~~~~~~~~^~~~~~~