/in/foo.cc:6:2: error: expected initializer before 'a'
  a[0] = a[n1-1];
  ^
/in/foo.cc:7:2: error: expected unqualified-id before 'for'
  for(int i = 1; i <= n1; i++){
  ^~~
/in/foo.cc:7:17: error: 'i' does not name a type
  for(int i = 1; i <= n1; i++){
                 ^
/in/foo.cc:7:26: error: 'i' does not name a type
  for(int i = 1; i <= n1; i++){
                          ^
/in/foo.cc:10:1: error: expected declaration before '}' token
 }
 ^