Compilare: main.cpp: In function 'int main()': main.cpp:62:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<mch.size();i++){ ~^~~~~~~~~~~ main.cpp:83:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<mch.size();i++){ ~^~~~~~~~~~~ main.cpp:92:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<mch0.size();i++){ ~^~~~~~~~~~~~