Compilare: user.cpp: In function ‘int main()’: user.cpp:64:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<d[i].size()-1;++j) ^ user.cpp: In function ‘int cb(int, int, int)’: user.cpp:45:1: warning: control reaches end of non-void function [-Wreturn-type] } ^