Compilare: main.cpp: In function 'int main()': main.cpp:46:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < cercuri.size() ; i++) ~~^~~~~~~~~~~~~~~~ main.cpp:64:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < cercuri.size()-1 ; i++) ~~^~~~~~~~~~~~~~~~~~