foo.cc: In function 'int main()':
foo.cc:27:2: error: 'sort' was not declared in this scope
  sort(a + 1, a + n + 1);
  ^~~~
foo.cc:27:2: note: suggested alternative:
In file included from /usr/include/c++/7/algorithm:62:0,
                 from foo.cc:4:
/usr/include/c++/7/bits/stl_algo.h:4856:5: note:   'std::sort'
     sort(_RandomAccessIterator __first, _RandomAccessIterator __last,
     ^~~~
foo.cc:21:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
foo.cc:23:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d", &a[i].Chinese, &a[i].Math, &a[i].English);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

自豪的采用 HydroJudger 进行评测(github.com/hydro-dev/HydroJudger)