Compilare: main.cpp: In function 'int solve()': main.cpp:89:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<number.size(); i++) ~^~~~~~~~~~~~~~ main.cpp:93:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==number.size()-1) ~^~~~~~~~~~~~~~~~~ main.cpp:107:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^