meeting some problem in pseudo code

I am converting a pseudo code which call greedy string tilling..and the pseudo code is

Greedy-String-Tiling(sToken,tToken)
{
  tiles={};
  do
  {
    searchLength=MinML;
    matches={};
   开发者_JAVA百科 ForallunmarkedtokenssTokensinsToken
    {
      ForallunmarkedtokensintTokensintToken
      {
        j=0;
        while(sToken+j==tToken+j&&unmarked(sToken+j)&&unmarked(tToken+j))
          j++;
        if(j==searchLength)
          matches=matches?match(s,t,j);
        elseif(j>searchLength)
        {
          matches={match(s,t,j)};
          searchLength=j;
        }
      }
    }
    Forallmatch(s,t,searchLength)?matches
    {
      Forj=0...(searchLength 1)
      {
        mark(sFiles+j);
        mark(tFilet+j);
      }
      tiles=tiles?match(s,t,searchLength);
    }
  }while(searchLength>MinML);
  returntiles;
} 

so, may i know what is meant by tiles={} and matches={}?? thanks..

I'm not familiar with that pseudocode "dialect", but I would assume that tiles={} and matches={} means to initialize these variables as new, empty sets/collections.