Compilare: user.c: In function ‘main’: user.c:27:16: warning: unused variable ‘j’ [-Wunused-variable] int n, i, d, j, f, a, b, m; ^ user.c:29:10: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%d%d", &n, &m ) ; ^ user.c:34:12: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%d%d%d", &a, &b, &d ) ; ^ user.c: In function ‘prim’: user.c:10:12: warning: ‘f’ is used uninitialized in this function [-Wuninitialized] while (f * f < cn ) { ^ user.c: In function ‘main’: user.c:10:12: warning: ‘f’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.c:8:7: note: ‘f’ was declared here int f, cn ; ^