Compilare: main.cpp: In function 'void multiplication(std::vector<long long int>&, std::vector<long long int>)': main.cpp:33:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 33 | while ( siz < a.size() + b.size() ) siz *= 2; | ~~~~^~~~~~~~~~~~~~~~~~~~~ main.cpp:36:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 36 | for ( int i = 0; i < a.size(); i ++ ) ca[i] = a[i]; | ~~^~~~~~~~~~ main.cpp:37:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 37 | for ( int i = 0; i < b.size(); i ++ ) cb[i] = b[i]; | ~~^~~~~~~~~~ main.cpp: In function 'void solve()': main.cpp:63:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 63 | for ( int i = 0; i < a.size(); i ++ ) { | ~~^~~~~~~~~~