Compilare: main.cpp: In function 'int main()': main.cpp:97:37: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 97 | for ( int j = 0 ; j < v [ i ] .size() ; j ++ ) | ~~^~~~~~~~~~~~~~~~~ main.cpp:107:44: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 107 | if ( first == false && sum == v[ i ] .size() ) | ~~~~^~~~~~~~~~~~~~~~~ main.cpp:119:41: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 119 | for ( int j = 0 ; j < v[ i ] .size() ; j ++ ) | ~~^~~~~~~~~~~~~~~~ main.cpp:81:15: warning: unused variable 'op' [-Wunused-variable] 81 | long long op = 30; | ^~