i need to make this program

saudyonline · October 23rd, 2004, 06:15 PM

i need to make the program to take a number between 2,9

and the program make possible combinations in form of sets where {1,2} the same as {2,1}
i don't need the program to display both sets.

also when you give the program a number between 2,9
for example :
for 2
{1,2}
for 3
{1,2,3}
for 4
{1,2,3,4}

and continue displaying all possible combination in a form of sets which contains a number of elements specified by the user of the program.

if you don't understand me please post a reply.

mehdi62b · October 24th, 2004, 05:51 AM

Do you need to make Subsets?
if so,i.e for 2
your program should generate these,
{},{1},{2},{1,2}
Did I guess your meaning correctly?

--------------------------------------------
Mehdi.:)

saudyonline · October 24th, 2004, 09:27 AM

look
if i have a set of {1,2,3,4,5,6,7,8,9,10}

for a combination of 2 the program will produce
{1,2} {1,3} {1,4} ... etc..
for a combination of 3 will produce
{1,2,3} {1,2,4} and so on.

with a condition that {1,2} equals {2,1} so no need to generate both, just one is enough

mehdi62b · October 24th, 2004, 01:25 PM

okay I got what you wanted,
I can tell you a way then you can write your program in your favorite syntax
suppose our set is {1,2,3},
then for generating Subsets we generate numbers between 0 to 2^3-1(in binary mode) then from these numbers we can determine which subset should be printed(under your circumstance,you should print some of them not all of them)
take a look at the numbers and their equivalent subsets,

000 <--->{}
001 <--->{3}
010 <--->{2}
011 <--->{2,3}
100 <--->{1}
101 <--->{1,3}
110 <--->{1,2}
111 <--->{1,2,3}

this I told gave you all possible combinations then for example for combination of 2 you should select numbers that have two 1 in their digits(I mean these numbers :011,101,110)
I think you can easily implement this logic and write your program.

--------------------------------------------
Mehdi.:)

saudyonline · October 24th, 2004, 06:14 PM

thank you for your reply

that is a good idea , but i think it doesn't match my problem.
my elements are stored in an array for example
A={a,b,c,d,e,f,g,h}
and i need to make possible combination between 2,3,..,5 elements without repeating

is your idea match that in your opinion

mehdi62b · October 25th, 2004, 06:21 AM

I think yes,
I think you didnt get my meaning completely,
suppose our set is {a,b,c} ...
now consider 101,the first digit is 1 so you print a,the second digit is 0 so you dont print b,and the third digit is 1,so you print c,and rest of them like above,

000 <--->{}
001 <--->{c}
010 <--->{b}
011 <--->{b,c}
100 <--->{a}
101 <--->{a,c}
110 <--->{a,b}
111 <--->{a,b,c}

then,
for combination of 0 you should select these numbers,
000(there is no 1 in these numbers)
for combination of 1 you should select these numbers,
001,010,100 (there is one 1 in these numbers)
for combination of 2 you should select these numbers,
011,101,110 (there are two 1's in these numbers)
for combination of 3 you should select these numbers,
111 (there are three 1's in these numbers)
in my opinion that solves your problem very well.

--------------------------------------------
Mehdi.:)

saudyonline · October 25th, 2004, 06:43 AM

if i ask you to write the code of that algorithm, is that will annoy you.

mehdi62b · October 25th, 2004, 12:25 PM

dont expect me to write your code,
anyway,
do these steps
suppose our set is {a,b,c}
1-make an Arraylist(the capacity is 2^3=8)
2-initialize that arraylist(set its every element to zero)
3-make a new method for increasing your arraylist one unit
4-make another method for getting the numbers of 1's in the ArrayList
5-put the increaser method in a loop cycle and check the elements of your array for matching the combinations
(I think I've explained them enough for you to write your code)
anyway,keep in touch in any faced problem.

--------------------------------------------
Mehdi.:)

mehdi62b · October 25th, 2004, 02:17 PM

Code:

////////////////////////////////////////////////////////////

        private void initialize(ref ArrayList a)
        {
            for(int i=0;i<a.Capacity;i++)
            {
                a.Add(0);
                //textBox1.Text+=a[i].ToString()+",";
            }
        }
        private void AddOneUnit(ref ArrayList a)
        {
            int i;
            for(i=a.Capacity-1;((Convert.ToInt32(a[i])==1)&&(i>0));i--)
                a[i]=0;
            a[i]=1;
        }
        private string print(ref ArrayList a)
        {
            string s="{";

            for(int i=0;i<a.Capacity;i++)
            {
                //if(System.Convert.ToInt32(a[i])==1)
                s+=a[i].ToString()+",";
            }
            s=s.Remove(s.Length-1,1);
            s+="}";
            return s;
        }
        private int GetTheNumbersOf1(ref ArrayList a)
        {
            int c=0;
            for(int i=0;i<a.Capacity;i++)
                if(System.Convert.ToInt32(a[i])==1) c++;
            return c;
        }
        private void button1_Click(object sender, System.EventArgs e)
        {
            const int m=3;//m is the lenght of your set
            const int n=8;//2^3
            const int combination=2;//get it from user
            string output="";
            ArrayList a=new ArrayList(m);
            this.initialize(ref a);
            for(int i=0;i<n;i++)
            {
                if(this.GetTheNumbersOf1(ref a)==combination)
                    output+=this.print(ref a)+"-";
                this.AddOneUnit(ref a);
            }
            output=output.Remove(output.Length-1,1);
            textBox1.Text=output;
        }
/*//////////////////////////////////////////////////////////
Copyright (c) 2004, Mehdi
Feel free to use and distribute in compiled form.
//////////////////////////////////////////////////////////*/

--------------------------------------------
Mehdi.:)

saudyonline · October 25th, 2004, 05:28 PM

thank you "mehdi"