Question

how to make logic of recursion function?

Answer 1

*
**
***
****

Answer 2

what do you mean? How does recursion work?

Answer 3

yes

Answer 4

Okay so basically there is iteration and recursion. Recursion is basically calling a method or function within itself to get an answer.

For example normally you would do an iteration like afor loop.

for(int i = 0; i < size; i++)
{
//do something
}

Answer 5

for recursion you would do

public void a()
int a = 0

while(a < 10)
{
a++
a();
}

Answer 6

which would call a again and again until you reached 9.

Answer 7

public void a()
{
int a = 0

while(a < 10)
{
a++
a();
}
}

Answer 8

forgot my brackets BAD KZ :P

Answer 9

*
**
***
****
print this using recurssion

Answer 10

you do know how to work strings right?

Answer 11

We aren't supposed to give out answers on here directly, but I am here to help if you need some guidance. I explained how recursion works, so let me know what you come up with :). There are many ways to complete this.

Answer 12

void main()
{
int a;
cin>>a;
spaces(a);
}
void spaces(int a)
{
cout<<" ";
if(a<1)
spaces(a-1);
asteric(a);
}
void asteric(int a)
{
cout<<"*";
if(a>1)
asteric(a-1);
cout<<endl;
spaces(a);
}

Answer 13

I personally would use an array, set each element to the # of * and then loop through the array.

Answer 14

woahs... You only need 1 method to do recursion. You're basically calling another 1 method from another, and then that method to the first one.

Answer 15

Like I said public void a()
{
//do something

a();

}

Answer 16

whats the mistake?

Answer 17

you're calling 2 methods, you need to call 1 method that calls itself.

Answer 18

i need to handle spaces as well as asteric

Answer 19

decrement in spaces and increment in asteric

Answer 20

oic okay, so basically you will take the number total lets say 10. The 10th one would be the *, then on the next line 9 and 10 will be **, etc. Again you use only 1 method.

Answer 21

Recursion is usually used either for traversal or when a problem can be broken into smaller, identical problems and their solution can be combined into the final answer.

In the case of traversals, this would be searching through a tree structure or graph or something similar.

In the case of sub-problems, as you're proceeding through the sub-problems, you're basically breaking down the larger problem. Once you reach the "base case" ( where you want to stop recursing ), you start to "unwind" the recursion ( proceeding back up ) which would be the combining of the sub-problems into the answer to the original, large problem. Generally, the first block of a recursive function is the test for the base case.

I'm not 100% sure of how you want to do your question, but if I'm given the length of the space/asterick string, I could decrement that length on the way down and keeping an original of the length (passing two variables), my base case being when that variable is 0. And on the unwind concatenate spaces up to original length minus this stack frame's length, padding it out with astericks and printing it. Or putting a linefeed on it and adding it to a (all of the strings) string and returning that up.

Answer 22

plus you can read this link...seems a good one:)

http://www.doc.ic.ac.uk/~wjk/C++Intro/RobMillerL8.html

Answer 23

^exactly what I was saying :p.