Compilare: user.cpp: In function ‘void prod(int*, int*, int)’: user.cpp:24:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<=a[0];i++) ^ user.cpp:32:31: warning: operation on ‘* b’ may be undefined [-Wsequence-point] b[++b[0]+1]=b[b[0]]/10; ^ user.cpp:23:26: warning: unused variable ‘r’ [-Wunused-variable] unsigned long long i,r=0; ^ user.cpp: In function ‘int main()’: user.cpp:38:17: warning: unused variable ‘l’ [-Wunused-variable] int n,k,i,j,l; ^