Compilare: main.cpp: In function 'int main()': main.cpp:170:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<4*chains[i].size();j++) ~^~~~~~~~~~~~~~~~~~~ main.cpp:169:13: warning: unused variable 'val' [-Wunused-variable] int val = chains[i].size(); ^~~ main.cpp:202:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos < mch.size() && mch[pos].vit <= viteza){ ~~~~^~~~~~~~~~~~