Compilare: main.cpp: In function 'int main()': main.cpp:22:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i <A.size(); ++i) { ~~^~~~~~~~~ main.cpp:26:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < A.size(); ++i) { ~~^~~~~~~~~~ main.cpp:40:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = A.size(); i < B.size(); ++i) { ~~^~~~~~~~~~