Permutation

Hi,
   I need one routine for permutation in my project as follows.

  I want 3 number combination from 1 to 15 numbers. Each combination should be put in a file, one combination per line as follows(comma seperated),

1,2,3
1,9,15
.
.
.

I want all the combinations.

Experts, help me

VeeramaniRaj
LVL 1
veeramaniAsked:
Who is Participating?
 
JaccoConnect With a Mentor Commented:
These are some routines I used for generating permutations. The algoritm uses string representing binary numbers. It is a non-recursive routine since recusion eats stack space. The starting string must have all 1 to the right of the string.

000000000000111 is the first

NextPerm permutes to the next state
CheckPerm checks whether a next permutation can be made

The routine can do something more of which I stripped some code. It can permute groups of bits inside the string. For example you can have two groups of six bits starting out as

000111000111

NextPerm(s, 1, 6) permutes the first part
NextPerm(s, 7, 6) permutes the second part

This way you can combine the statistics for 3 out of 6 with another 3 out of six. Maybe this is usefull in you code as well.

MakeInit is used when using groups.

When using groups you have to call NextPerm hierarchically

Hope this works for you

Regards Jacco

procedure MakeInit(var s: String; iStart, iLength: Integer);
var
  SubStr: String;
  iPos: Integer;
  TempStr: String;
begin
  TempStr := '';
  SubStr := Copy(s,iStart,iLength);
  for iPos:=1 to Length(SubStr) do
    if SubStr[iPos]='1' then TempStr := TempStr + '1';
  for iPos:=Length(TempStr)+1 to iLength do
    TempStr := '0' + TempStr;
  Delete(s,iStart,iLength);
  Insert(TempStr,s,iStart);
end;

function NextPerm(var s: String; iStart, iLength: Integer): Boolean;
var
  SubStr: String;
  iPos1,iPos2: Integer;
begin
  Result := False;
  SubStr := Copy(s,iStart,iLength);
  if Pos('0',SubStr)=0 then Exit;
  iPos1 := Pos('01',SubStr);
  iPos2 := Pos('1',SubStr);
  if iPos1<>0 then begin
    Delete(SubStr,iPos1,2);
    Insert('10',SubStr,iPos1);
    if (iPos2 <> 0) and (iPos2 < iPos1) then begin
      MakeInit(SubStr,1,iPos1-1);
    end;
    Delete(s,iStart,iLength);
    Insert(SubStr,s,iStart);
    Result := True;
  end;
end;

function CheckPerm(s: String; iStart, iLength: Integer): Boolean;
var
  SubStr: String;
begin
  Result := False;
  SubStr := Copy(s,iStart,iLength);
  if Pos('0',SubStr)=0 then Exit;
  if Pos('01',SubStr)=0 then Exit;
  Result := True;
end;

procedure OutputLine(var F: TextFile; const s: string);
var
  i: Integer;
  b: Boolean;
begin
  b := True;
  // Form1.Memo1.Lines.Add(IntToStr(i)+' - '+s);
  for i := 1 to Length(s) do
    if s[i] = '1' then
    begin
      if b then
        b := False
      else
        Write(F, ',');
      Write(F, IntToStr(i));
    end;
  WriteLn(F);
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  s: String;
  i: Integer;
  t1: TDateTime;
  F: TextFile;
begin
  AssignFile(F, 'c:\permutations.csv');
  try
    Rewrite(F);
    s := '000000000000111';
    i := 0;
    t1 := Now;
    while CheckPerm(s,1,15) do begin
      OutputLine(F, s);
      NextPerm(s,1,15);
      OutputLine(F, s);
      Inc(i);
    end;
    OutputLine(F, s);
    t1 := Now - t1;
    Memo1.Lines.Add(IntToStr(i) + ' perms in second: '+FloatToStrF(t1*60*60*24,ffFixed,15,2));
  finally
    CloseFile(F);
  end;
end;
0
 
JohnchCommented:
Here is some code, just add a button with the following code.


John.



procedure TForm1.Button1Click(Sender: TObject);
var f:textfile;
num1,num2,num3:integer;
begin
          assignfile(f,'c:\numbers.csv');
          if not fileexists('c:\numbers.csv') then
               rewrite(F)
          else
               append(f);
          for num1 := 1 to 15 do
          begin
               for num2:= 1 to 15 do
               begin
                    for num3:=1 to 15 do
                    begin
                    writeln(f,inttostr(num1),',',inttostr(num2),',',inttostr(num3));
                    end;
               end;

          end;
          closefile(f);
end;
0
 
ziolkoCommented:
veermani do You want include combinations like : 1,1,1 ; 2,2,2 ??
ziolko.
0
Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

 
veeramaniAuthor Commented:
No, I don't want 1,1,1, even 1,1,2 also. The numbers should not be repeated in the combination.
0
 
kotanCommented:
try this for not repeating.

 for num1 := 1 to 15 do
 begin
    for num2:= 1 to 15 do
    begin
       if num2 <> num1 then begin
          for num3:=1 to 15 do
          begin
             if num3 <> num1 and num3 <> num2 then begin                             writeln(f,inttostr(num1),',',inttostr(num2),',',inttostr(num3));
          end;
          end;
       end;
    end;
 end;
0
 
karouriCommented:
This is a code that permutes any string you give, making all possible permutations. It needs a little modification to insert the commasunit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    ListBox1: TListBox;
    procedure Edit1KeyPress(Sender: TObject; var Key: Char);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure Permute(s:string;sl:TStrings);
var
  slbuf:TStringList;
  i,j:integer;
begin
  if Length(s)=2 then
  begin
    sl.Clear;
    sl.Add(s);
    sl.Add(s[2]+s[1]);
    exit;
  end;
  slbuf:=TStringList.Create();
  try
    sl.Clear;
    for i:=1 to Length(s) do
    begin
      Permute(Copy(s,1,i-1)+Copy(s,i+1,length(s)),slbuf);
      for j:=0 to slbuf.Count-1 do
        sl.Add(s[i]+slbuf[j]);
    end;
  finally
    slbuf.Free;
  end;
end;

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
  if key=#13 then
  begin
    Permute(Edit1.Text,ListBox1.Items);
  end;
end;

end.

0
 
JohnchCommented:
So you don't want all the combinations.

0
 
veeramaniAuthor Commented:
Hi Karouri,
            Is it working in your computer?
0
 
kotanCommented:
Hi veeramani,
     is my method work fine for your requirement.

Best Regards,
kotan
0
 
veeramaniAuthor Commented:
Hi Kotan,
         It's working, but repeating
i mean , it gives 1 2 3 as well as 1 3 2

I want unique combinations after sorting
0
 
ziolkoCommented:
for i1:=1 to 15 do
  for i2:=i1+1 to 15 do
    for i3:=i1 to 15 do
      comb:=InttoStr(i1)+','+IntToStr(i2)+','+IntToStr(i3)
0
 
ziolkoCommented:
for i1:=1 to 15 do
  for i2:=1 to 15 do
    if i2<>i1 then
      for i3:=i1 to 15 do
      comb:=InttoStr(i1)+','+IntToStr(i2)+','+IntToStr(i3)
0
 
ziolkoCommented:
ooops sorry second comment is ok so ignore first one :-))
ziolko.
0
 
kotanCommented:
I think should be like this,

for i1:=1 to 15 do
   for i2:=i1+1 to 15 do
        for i3:=i2+1 to 15 do
          comb:=InttoStr(i1)+','+IntToStr(i2)+','+IntToStr(i3)
0
 
veeramaniAuthor Commented:
All restricted to only limit of three, but, if i change it to some 6 or 7, it won't work. I want a algorithamic approch.

Regards,

veeramaniraj
0
 
JohnchCommented:
Surely if you want unique then all you increment is the outside value. Like this.


procedure TForm1.Button1Click(Sender: TObject);
var f:textfile;
num1,num2,num3:integer;
begin
         assignfile(f,'c:\numbers.csv');
         if not fileexists('c:\numbers.csv') then
              rewrite(F)
         else
              append(f);
         num1 := 1;
         num2:= 2;
         
                   for num3:=3 to 15 do
                   begin
                   writeln(f,inttostr(num1),',',inttostr(num2),',',inttostr(num3));
                   end;
             

         
         closefile(f);
end;
0
 
JohnchCommented:
Surely if you want unique then all you increment is the outside value. Like this.


procedure TForm1.Button1Click(Sender: TObject);
var f:textfile;
num1,num2,num3:integer;
begin
         assignfile(f,'c:\numbers.csv');
         if not fileexists('c:\numbers.csv') then
              rewrite(F)
         else
              append(f);
         num1 := 1;
         num2:= 2;
         
                   for num3:=3 to 15 do
                   begin
                   writeln(f,inttostr(num1),',',inttostr(num2),',',inttostr(num3));
                   end;
             

         
         closefile(f);
end;
0
 
karouriCommented:
my method is working on my computer, but the following problem may have happened to you:
It uses recursion in a memory intensive way. I will post another method that uses much less memory later..
0
 
kotanCommented:
This is a solution using recursive method, may be there are some syntax error. Because I am new to Delphi.

procedure permute(r: Integer, n: Integer)
strP: string[r];
begin
    recurpermute(r, n, 0, strP);
end;

procedure recurpermute(r: Integer, n: Integer, loop: Integer, strP: string)
i, c: Integer;
begin
    for i := loop + 1 to n do
    begin
        strP[r] := i;
        if r <> 1 then
        begin
            recurpermute(r - 1, n, i, strP);
        end else
        begin
            for c := strP[0] downto 1 do
            begin
                write(f, strP[c]);
                if c <> 1 then
                    write(', ')
                else
                    writeln();
            end;
        end;
    end
end;

Hope this helps.

Best Regard,
kotan
0
 
karouriCommented:
I am sorry, I think I have overlooked the 'combinations not permutations' question..
0
 
JaccoCommented:
Sorry you should delete the second OutputLine in the last procedure

Regards
0
 
JaccoCommented:
Here is the correct Button1Click

procedure TForm1.Button1Click(Sender: TObject);
var
  s: String;
  i: Integer;
  t1: TDateTime;
  F: TextFile;
begin
  AssignFile(F, 'c:\permutations.csv');
  try
    Rewrite(F);
    s := '000000000000111';
    i := 0;
    t1 := Now;
    while CheckPerm(s,1,15) do begin
      OutputLine(F, s);
      NextPerm(s,1,15);
      Inc(i);
    end;
    OutputLine(F, s);
    t1 := Now - t1;
    Memo1.Lines.Add(IntToStr(i) + ' perms in second: '+FloatToStrF(t1*60*60*24,ffFixed,15,2));
  finally
    CloseFile(F);
  end;
end;
0
 
VSFCommented:
This is a Complete Pascal7 program to make permutation of  given numbers!
It can be easily converted to delphi!

Hope this helps!
VSF
www.victory.hpg.com.br


Program permutations;

Uses Crt;

Type hold_em_here = Array[1..15] of Integer;

Var  numbers,combs,bot2a : Integer;
     ans,top,bot1,bot2b : Real;
     hold_Array : hold_em_here;

Function permutate_this(number1 : Integer) : Real;
Var i : Integer;
    a : Real;
begin
 a := number1;
 For i := (number1 - 1) doWNto 1 do a := a  * i;
 permutate_this := a;
end;

Procedure input_numbers(Var hold_Array : hold_em_here; counter : Integer);
Var i,j : Integer;
begin
 For i := 1 to counter do begin
  Write(' Input #',i:2,': ');
  READLN(j);
  hold_Array[i] := j;
 end;
end;

Procedure show_numbers(hold_Array : hold_em_here; counter : Integer);
Var i,j : Integer;
begin
 WriteLN;
 Write('Array looks like this: ');
 For i := 1 to counter do Write(hold_Array[i]:3);
 WriteLN
end;

begin
 ClrScr;
 WriteLN;
 WriteLN('  Permutations');
 WriteLN;
 Write('     Enter number of digits (1-15): ');
 READLN(numbers);
 Write('Enter number in combination (2-10): ');
 READLN(combs);
 top := permutate_this(numbers);
 bot1 := permutate_this(combs);
 bot2a := numbers - combs;
 bot2b := permutate_this(bot2a);
 ans := top/(bot1*bot2b);
 WriteLN('   total permutations For above is: ',ans:3:0);
 WriteLN;
 input_numbers(hold_Array,numbers);
 show_numbers(hold_Array,numbers);
END.
0
 
JaccoCommented:
Veeramani? Are you still with us?

Jacco
0
 
veeramaniAuthor Commented:
Listening.....
0
 
JaccoCommented:
Are you going to grade the question?

Regards Jacco
0
All Courses

From novice to tech pro — start learning today.