foo.c: In function 'main':
foo.c:29:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   29 |  scanf("%d%d",&n1,&n2);
      |  ^~~~~~~~~~~~~~~~~~~~~
foo.c:31:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   31 |   scanf("%d",a+j);
      |   ^~~~~~~~~~~~~~~
foo.c:33:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   33 |   scanf("%d",b+j);
      |   ^~~~~~~~~~~~~~~
foo.c: In function 'FindiSecondMax':
foo.c:23:8: warning: 'r2' may be used uninitialized in this function [-Wmaybe-uninitialized]
   23 | return r2;
      |        ^~
foo.c:17:15: warning: 'r1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   17 |  if(a[i] >max2&&i!=r1)
      |     ~~~~~~~~~~^~~~~~~

[Hydro](https://hydro.ac)提供评测服务