Compilare: main.cpp: In function 'int main()': main.cpp:33:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < drumuri[1].size(); ++ i) ~~^~~~~~~~~~~~~~~~~~~ main.cpp:49:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < drumuri[a].size(); ++ i) ~~^~~~~~~~~~~~~~~~~~~