Compilare: user.cpp: In function ‘void bf(int, int&)’: user.cpp:17:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<a[i].size();j++) ^ user.cpp: In function ‘void bf_niv(int, int&)’: user.cpp:38:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<a[i].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:75:15: warning: unused variable ‘j’ [-Wunused-variable] int x,y,i,j; ^ user.cpp:93:13: warning: ‘t’ may be used uninitialized in this function [-Wmaybe-uninitialized] bf(t,t1); ^