As some people noticed this was broken. Fixed version is not quite as fast, but still faster than functional C++:

  Goats Wolves Lions    C++11  Nimrod
     17     55     6     0.00    0.03
    117    155   106     0.17    0.13
    217    255   206     0.75    0.62
    317    355   306     2.16    1.89
    417    455   406     5.28    4.34
    517    555   506    10.75    8.42
    617    655   606    19.15   14.45
    717    755   706    31.58   23.04
    817    855   806    46.52   33.69
    917    955   906    67.94   48.57
   1017   1055  1006    93.75   65.25
   2017   2055  2006   731.42  500.95