In fact, it is simpler than a hash. The provided code is not complete (the limit to 1 hour is missing). Here is a full functional solution to its problem:

  perl -MDigest::MD5 -nle '($id,@data)=split;$t=time;$j=unpack("L", Digest::MD5::md5($id))%100;print join(" ",$id,@data) if $t-$h{$j}>3600 or $hi{$j} ne $id;$h{$j}=$t;$hi{$j}=$id' input