foo.cc: In function 'int main()':
foo.cc:11:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
foo.cc:14:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a[i].power);
   ~~~~~^~~~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务