# Help in converting a certain recurtion

## Main Question or Discussion Point

here is a question and i have a very similar code but i need to convert it
some how in order to fit this question

question:
In order to make their phone numbers more memorable, service providers like to find numbers that spell out some word (called a mnemonic) appropriate to their business that makes that phone number easier to remember. For example, the phone number for a recorded time-of-day message in some localities is 637-8687 (NERVOUS). Imagine that you have just been hired by a local telephone company to write a method listMnemonics that will generate all possible letter combinations that correspond to a given number, represented as a string of digits. For example, if you call
recursiveObject.listMnemonics("723")
your method shall generate and print out (using recursion) the following 27 possible letter combinations that correspond to that prefix:
PAE PBE PCE RAE RBE RCE SAE SBE SCE
PAF PBF PCF RAF RBF RCF SAF SBF SCF

my efforts in solving it:
i know that in order to solve this question is need to use a recursive methos that
prints out all the subsets of a given string letters with a given resolt string size

i have built this code
Code:
ublic class subsets {

/**
* @param args
*/
public static void main(String[] args) {
String word="abcd";

subsets(word.length(),3,"",word);
}
public static void phone(String phone){

}
public static void subsets(int n,int k,String also,String word){
if (n==0){
if (also.length()==k){
System.out.println(also);
}
}
else{
subsets(n-1,k,also+word.charAt(n-1),word);
subsets(n-1,k,also,word);

}
}

}

Last edited:

## Answers and Replies

Related Programming and Computer Science News on Phys.org
i had a theoretical idea the we put an inner counter for each cell
and then count them like numbers
001
002
003
but for example in order to have a combination for a number with length 4
we need to have 4 "for" loops one inside another

for 5 digit number we need to have 5 "for" loop one inside of the other

how do i solve its for every given length