recursion

[anna2611]

I need help,please tell me how to solve this:
prime factoring program with recursion
example:

16=2^4;
20=2^2*5
24=2^3*3;

[sicarie]

The experts on this site are more than happy to help you with your problems but they cannot do your assignment/program for you. Attempt the assignment/program yourself first and post questions regarding any difficulties you have or about a particular function of the code that you don't know how to achieve.

Please read the Posting Guidelines and particularly the Coursework Posting Guidlines.

Then when you are ready post a new question in this thread.

MODERATOR

[anna2611]

this is the problem.I solve this,but without recursion.But I really don't now how to use recursion here:

#include<iostream.h>
void main()
{
    int n,p;
    cout<<"n=";
    cin>>n;
    p=2;
    do{
        int k=0;
        while(n%p==0 && n!=1){
            n=n/p;
            k=k+1;
        }
        if (k>0)
            cout<<p<<"^"<<k;
        p++;
    }while(n!=1);
}

[anna2611]

"thank you" for "help" i solve the problem alone

CODE EDITED OUT BY ADMIN
 

[Ganon11]

It doesn't look like this problem is using recursion at all. You've put the operations inside a function, but that function does not call itself, so it is not recursive.

[MMcCarthy]

Sorry I had to edit out the code in Post #4. Please see the FAQ on Posting guidelines for homework questions.

ADMIN

[anna2611]

So?!!Tell me how to do that!!!

It doesn't look like this problem is using recursion at all. You've put the operations inside a function, but that function does not call itself, so it is not recursive.

[anna2611]

OK,Sorry :-(

Sorry I had to edit out the code in Post #4. Please see the FAQ on Posting guidelines for homework questions.

ADMIN

[Ganon11]

Well, once you divide the number by a factor, the prime factors include the number you just divided plus the prime factors in the new number.

Example: For 16, I would start by dividing by 2. Now I know 2 is one of the factors, and I've got to find the prime factors of 16 / 2 = 8. So use the primefactor() function again.

Your end condition will be when the number is 1 - at this point, you have found all the factors.