Compilare: main.cpp: In function 'int main()': main.cpp:33:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = b.size() + 1; i < ans.size(); ++i){ ~~^~~~~~~~~~~~ main.cpp:37:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a.size(); ++i){ ~~^~~~~~~~~~ main.cpp:46:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i <= b.size() / 2; ++i){ ~~^~~~~~~~~~~~~~~