Compilare: user.c: In function ‘G’: user.c:8:5: warning: implicit declaration of function ‘isdigit’ [-Wimplicit-function-declaration] while(!isdigit(c)) ^ user.c: In function ‘main’: user.c:20:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("stalpisori.in","r",stdin); ^ user.c:21:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("stalpisori.out","w",stdout); ^ user.c:22:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^