Possible difference in compilers?

[Charles via Digitalmars-d-learn]

Hi everyone

So I've been working on the problems over at HackerRank.com
trying to gain some familiarity with D. I use a Windows computer
with VisualD, but the server used to test the program uses Ubuntu
(I can't tell which compiler they're actually using).

The problem I'm stuck on now is the Utopian Tree
(https://www.hackerrank.com/challenges/utopian-tree).

My solution I came up with (and works locally) is:

import std.stdio;
void main() {
      int height=1,t=1,oldN=0,n;
      readf(" %d\n", &t);
      foreach (i;0 .. t) {
          readf(" %d\n", &n);
          foreach (j; oldN .. n)
              height = (j % 2) ? height + 1 : height * 2;
          writeln(height);
          oldN = n;
      }
}

For the test cases this only produces the first output
(correctly), but then hits a compiler error with format.d before
the next one. Any ideas what might be going on?

Thanks,
Charles