Compilare: user.cpp: In function ‘void toint()’: user.cpp:16:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v.size();i++) ~^~~~~~~~~ user.cpp: In function ‘void imp_vec()’: user.cpp:37:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b.size();i++) ~^~~~~~~~~ user.cpp: In function ‘long long int put(long long int, int)’: user.cpp:56:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < b.size() and !ok; ++i) ~~^~~~~~~~~~ user.cpp:77:1: warning: control reaches end of non-void function [-Wreturn-type] } ^