Compilare: main.cpp: In function 'int main()': main.cpp:16:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 2, lung = 0; i <= a.size() - 1; i++) ~~^~~~~~~~~~~~~~~ main.cpp:30:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1, lung = 0; i <= b.size() - 1; i++) ~~^~~~~~~~~~~~~~~ main.cpp:38:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(lung == a.size() - 1) ~~~~~^~~~~~~~~~~~~~~