Compilare: user.cpp: In function ‘void bf(int, int)’: user.cpp:12:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[k].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:64:49: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[i].size();j++) ^ user.cpp:67:49: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[i].size();j++) ^ user.cpp:63:29: warning: unused variable ‘nr1’ [-Wunused-variable] int nr1=0; ^