Compilare: main.cpp: In function 'Int operator*(Int, int)': main.cpp:69:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0, t = 0; i < a.size() || t; i++, t /= B) { ~~^~~~~~~~~~ main.cpp:70:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i < a.size()) ~~^~~~~~~~~~