foo.cpp:1:1: error: 'include' does not name a type
 include<iostream>
 ^
foo.cpp: In function 'int main()':
foo.cpp:8:2: error: 'cin' was not declared in this scope
  cin>>n;
  ^
foo.cpp:9:2: error: 'cout' was not declared in this scope
  cout<<a[n];
  ^
foo.cpp:6:6: warning: unused variable 'i' [-Wunused-variable]
  int i;
      ^