foo.cc:4:1: error: expected initializer before ‘int’
    4 | int visit[2001];
      | ^~~
foo.cc: In function ‘int main()’:
foo.cc:7:16: error: ‘visit’ was not declared in this scope
    7 |         memset(visit,0,sizeof(visit));
      |                ^~~~~
foo.cc:7:16: note: ‘std::visit’ is only available from C++17 onwards
foo.cc:12:22: error: ‘h2’ was not declared in this scope; did you mean ‘h1’?
   12 |                 cin>>h2[i];
      |                      ^~
      |                      h1
foo.cc:16:34: error: unable to find numeric literal operator ‘operator""h’
   16 |                         if(h1[i]>2h[j]&&h2[j]!=0&&visit[j]==1)
      |                                  ^~
foo.cc:16:34: note: use ‘-fext-numeric-literals’ to enable more built-in suffixes
foo.cc:16:41: error: ‘h2’ was not declared in this scope; did you mean ‘h1’?
   16 |                         if(h1[i]>2h[j]&&h2[j]!=0&&visit[j]==1)
      |                                         ^~
      |                                         h1