From NOELL%DWIFH1.BITNET@wiscvm.wisc.edu Thu Sep  3 12:56:25 1987
Date:         Thu, 03 Sep 1987 19:35 CET
From: Karl-L. Noell <NOELL%DWIFH1.BITNET@wiscvm.wisc.edu>


---------------- CUT HERE  to get  BUBBLE.PAS  -------------------------

                                            { K.L. Noell, fhw 03.Sep.87 }
 PROGRAM BubbleSort_Demo (output);

 CONST n = 639;                   { number of columns :  x-coordinates }
       range = 199;               { actual values :      y-coordinates }
 VAR
      i1: INTEGER;
      num,loops,swaps,aloops,aswaps: REAL;
      A: ARRAY [0..n] OF INTEGER;


 PROCEDURE BubbleSort ( np: INTEGER );
 VAR
     i,ie,temp: INTEGER;
     flag: BOOLEAN;

 BEGIN
     ie := np;

     REPEAT
        flag := FALSE;
        ie := ie - 1;
        FOR i:= 0 TO ie DO BEGIN
            loops := loops + 1;
            IF A[i] > A[i+1] THEN     { swap }
               BEGIN
               flag := TRUE;
               swaps := swaps + 1;
               Plot (i,A[i],0);
               Plot ((i+1),A[i+1],0);
               temp := A[i];
               A[i] := A[i+1];
               A[i+1]:= temp;
               Plot(i, A[i] ,3);
               Plot((i+1),A[i+1],3);
            END;
        END;
     UNTIL flag = FALSE;

 END;  { BubbleSort }


{ ----------------------------------------- }

 Begin  { Mainprogram for BubbleSort_Demo }

    HiRes;
    HiResColor (Magenta);

    FOR i1:=1 TO n DO BEGIN
       num := range*RANDOM;
       A [i1] := TRUNC (num);
       Plot (i1,A[i1],15);
    END;

   GraphBackground (Magenta);
   Palette (2);

  {Sorting start:}
  loops := 0;
  swaps := 0;
  DELAY (1000);

     BubbleSort (n);

     aloops := loops;
     aswaps := swaps;
     writeln ('   Bubble Sort a)  Loops,Swaps: ',loops,swaps);
     writeln;
     writeln ('b) Press any key to process with an array already sorted,');
     writeln ('   but in opposite direction.');

     REPEAT UNTIL KeyPressed;

  Hires;
  GraphBackground(6);
  Palette(2);
    FOR i1:=1 TO n DO BEGIN
       num := (n-i1)/(n/range);
       A[i1] := TRUNC (num);
       Plot (i1,A[i1],15);
    END;

  loops := 0;
  swaps := 0;
  DELAY (1000);

  BubbleSort (n);

  REPEAT UNTIL KeyPressed;

     writeln (' Bubble Sort a)  Loops,Swaps: ',aloops,aswaps);
     writeln (' Bubble Sort b)  Loops,Swaps: ',loops,swaps);
     writeln;
     writeln (' Press any key to exit.');

     REPEAT UNTIL KeyPressed;
     TextMode;

end. { BubbleSort_Demo }



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