Compilare: user.c: In function ‘print’: user.c:44:5: warning: array subscript has type ‘char’ [-Wchar-subscripts] s[k++]=x%10+'0'; ^ user.c:48:5: warning: array subscript has type ‘char’ [-Wchar-subscripts] nextp(s[--k]); ^ user.c: In function ‘main’: user.c:86:3: warning: left shift count >= width of type [enabled by default] f[n]=(1<<63); ^ user.c: In function ‘nextr’: user.c:17:10: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, LU, 1, fin); ^