procedure sort( var r : ArrayToSort; lo, up : integer );

     var  i, j : integer;

          tempr : ArrayEntry;

     begin

     while up>lo do begin

          i := lo;

          j := up;

          tempr := r[lo];

          {*** Split file in two ***}

          while i
               while r[j].k > tempr.k do

                    j := j-1;

               r[i] := r[j];

               while (i
                    i := i+1;

               r[j] := r[i]

               end;

          r[i] := tempr;

          {*** Sort recursively ***}

          sort(r,lo,i-1);

          lo := i+1

          end

     end;

c version

sort( r, lo, up )

     ArrayToSort r;

     int lo, up;
     {int i, j;

     ArrayEntry tempr;

     while ( up>lo ) {

          i = lo;

          j = up;

          tempr = r[lo];

          /*** Split file in two ***/

          while ( i
               for ( ; r[j].k > tempr.k; j-- );

               for ( r[i]=r[j]; i
               r[j] = r[i];

               }

          r[i] = tempr;

          /*** Sort recursively, the smallest first ***/

          if ( i-lo < up-i ) { sort(r,lo,i-1);  lo = i+1; }

               else    { sort(r,i+1,up);  up = i-1; }

          }

     }