/in/foo.c: In function 'main':
/in/foo.c:5:11: error: 'new' undeclared (first use in this function)
  int* a = new int[n];
           ^~~
/in/foo.c:5:11: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:5:15: error: expected ',' or ';' before 'int'
  int* a = new int[n];
               ^~~