Compilare: main.cpp: In function 'int main()': main.cpp:37:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 37 | for(int i=0; i<v[cate].size(); ++i) | ~^~~~~~~~~~~~~~~ main.cpp:47:27: 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=0; i<v[cate].size(); ++i) | ~^~~~~~~~~~~~~~~ main.cpp:60:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 60 | for(int i=0; i<v[cate].size(); ++i) | ~^~~~~~~~~~~~~~~ main.cpp: In function 'int hashi(int)': main.cpp:22:12: warning: 'bucket' may be used uninitialized [-Wmaybe-uninitialized] 22 | return bucket; | ^~~~~~ main.cpp:15:9: note: 'bucket' was declared here 15 | int bucket, put=1; | ^~~~~~ In file included from /usr/include/c++/12.2.1/vector:64, from main.cpp:4: In member function 'constexpr void std::vector<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = int; _Alloc = std::allocator<int>]', inlined from 'int main()' at main.cpp:43:34: /usr/include/c++/12.2.1/bits/stl_vector.h:1283:13: warning: 'bucket' may be used uninitialized [-Wmaybe-uninitialized] 1283 | ++this->_M_impl._M_finish; | ^~ main.cpp: In function 'int main()': main.cpp:15:9: note: 'bucket' was declared here 15 | int bucket, put=1; | ^~~~~~