foo.c: In function ‘main’:
foo.c:4:9: error: ‘cin’ undeclared (first use in this function)
    4 |         cin>>n;
      |         ^~~
foo.c:4:9: note: each undeclared identifier is reported only once for each function it appears in
foo.c:8:17: error: ‘cout’ undeclared (first use in this function)
    8 |                 cout<<1<<endl;
      |                 ^~~~
foo.c:8:26: error: ‘endl’ undeclared (first use in this function)
    8 |                 cout<<1<<endl;
      |                          ^~~~
foo.c:14:19: error: expected expression before ‘<’ token
   14 |         {   cout<<<1<<" "<<1<<" "<<2<<" ";
      |                   ^
foo.c:20:28: error: invalid suffix "；" on integer constant
   20 |                         i+=1；
      |                            ^~~
foo.c:20:31: error: expected ‘;’ before ‘}’ token
   20 |                         i+=1；
      |                               ^
      |                               ;
   21 |                 }
      |                 ~