foo.c: In function 'main':
foo.c:5:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    5 |     scanf("%d",&n);
      |     ^~~~~~~~~~~~~~
foo.c:7:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    7 |         scanf("%d",&a[i]);
      |         ^~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务