foo.c: In function 'main':
foo.c:22:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   22 |  scanf("%d",&n);
      |  ^~~~~~~~~~~~~~
foo.c:25:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   25 |   scanf("%d",&a[i]);
      |   ^~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务