Developing Algorithm to Recursively Walk Array: arr[4] Example

[anonim]

TL;DR Summary

to walk around the array

I want to write code walk around the array recursively. For some reason I cannot share my code. Let's say I have a array like this: arr[4], I want to look 012 123 013 or 01 12 23 02 03 13. In code I write I can look 012 123 or 01 12 23 but I cannot look 013 or 02 03 13. What algorithm should I develop?

 

[Filip Larsen]

It sounds like you want to "visit" selected combinations of array indices in your array. If so, you may want to look at a similar question in https://www.physicsforums.com/threads/algorithm-to-return-all-subarrays-of-a-given-array.877437/

This is not a particularly recursive algorithm, so perhaps you can elaborate on why you think you need recursion (that is, what problem are you trying to solve)?

 

[Mark44]

This is not a particularly recursive algorithm, so perhaps you can elaborate on why you think you need recursion (that is, what problem are you trying to solve)?

"If the only tool you have is a hammer, everything begins to look like a nail."
The OP has started a number of threads with the goal of trying to solve some problem by the use of recursion. For some of the problems, recursion isn't a viable solution.

 

[jim mcnamara]

@Mark44 - that is a great concept-
"If the only tool you have is a hammer, everything begins to look like a nail."
Where did you encounter that?

 

[Mark44]

@Mark44 - that is a great concept-
"If the only tool you have is a hammer, everything begins to look like a nail."
Where did you encounter that?

It might have been in a programming class I took back in the early 80s.

 

[Svein]

I started to sketch such a recursive program, but I had not written more than 7 or 8 lines before i stopped. I suddenly discovered that my mantra in programming was not satisfied - I had not written a requirement spec (what is the desired output of the program) or a program design (how do we go about solving this using a recursive method). And then I found out that it was too much work anyhow.

 

[Svein]

One thing I thought of late yesterday night: You need a "sentinel" (meaning end-of-sequence) in your list (otherwise you will only get resulting sequences the same size as your list of symbols).

 

[.Scott]

@Mark44 - that is a great concept-
"If the only tool you have is a hammer, everything begins to look like a nail."
Where did you encounter that?

It is related to the "Golden Hammer".
But the first use I heard of it was in the early 1980's.
The US Senate was looking at the burgeoning use of CT Scan machines - and the problems that were arising when more of these machines were being purchased by hospitals within a market area then the patient population in that area could ever use. One Senator's remark went something like this: If you've just spent $3 million on a CT Scanner, everything looks like a nail.

 

[sysprog]

@Mark44 - that is a great concept-
"If the only tool you have is a hammer, everything begins to look like a nail."
Where did you encounter that?

I heard it as "give a kid a hammer, and everything needs poundin'" $-$ in various forms, it's an old saw.