foo.c: In function 'main':
foo.c:7:15: warning: unused variable 'max' [-Wunused-variable]
  int i, a[N], max, n;
               ^~~
foo.c:8:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ^~~~~~~~~~~~~~~
foo.c:10:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a[i]);
   ^~~~~~~~~~~~~~~~~~
foo.c: In function 'Findmax':
foo.c:25:9: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return b;
         ^

[Hydro](https://hydro.ac)提供评测服务