Compilare: user.c:3:1: warning: return type defaults to ‘int’ [enabled by default] main(){freopen("stramosi.in","r",stdin);freopen("stramosi.out","w",stdout); ^ user.c: In function ‘main’: user.c:3:15: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] main(){freopen("stramosi.in","r",stdin);freopen("stramosi.out","w",stdout); ^ user.c:3:48: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] main(){freopen("stramosi.in","r",stdin);freopen("stramosi.out","w",stdout); ^ user.c:4:6: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.c:5:21: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] for(i=0;i++<n;)scanf("%d",a[0]+i); ^ user.c:7:17: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] for(;m--;){scanf("%d %d",&j,&i); ^