foo.c: In function 'main':
foo.c:16:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n1, &n2);
     ^~~~~~~~~~~~~~~~~~~~~~~~
foo.c:18:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &a[i]);
         ^~~~~~~~~~~~~~~~~~
foo.c:20:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &b[i]);
         ^~~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务