Please help me with this problem? :(

[chottachatri]

hello,

the problem question is :-
1) there is a file given in which words are stored

2)we have to make T9 dictionary that's available in our cellphones


User can input for example 223 so the output should be every meaningful word that comes from this combination like bad,ace etc..


(223 means similar to our cellphones where 2=abc 3=def 4=ghi..)

Just give me few logics then i will try to make it but i am not getting a general idea i want somebody to give me general idea only!

i know we need permutations in this program but how??Please explain me in better way

[matsp]

So, what have you done so far?

--
Mats

[chottachatri]

I haven't done anything i don't know from where to start and where to end in this program Please give me general idea so that i can start coding on it!

[CornedBee]

The key to this problem is the dictionary structure. It has to be a special form of a trie. It works basically like this: the dictionary is a large tree. At every level, it splits into 9 subtrees (digits 1-9). Every node contains all the words that are possibly formed by the digit chain used to reach it.
You should be able to work from here.

[matsp]

Well, before you start writing code you will need to think about HOW you should implement the code - this is called a "design". Depending on the project and the experience of the people involved, you may find that writing a 30 page document, or just write down a few data structures and a few lines of text is the right thing to do, but whatever you do, you need to have a "plan" for your software design. Just like you wouldn't build a house without at least drawing a few lines on a piece of paper to figure out what it's going to look like. If you are building a rabbit hutch, you may be able to get away with "just doing it". Same with a "hello world" program.

Obviously, the more experience you have, the more knowledge you have, and the less detailed the plan needs to be. But you need some sort of general plan - even a master builder will need to do some work before starting the actual building work, right?

So, how would you store the data (data structures), how do you find the matching strings from the data (methods/algorithms) etc, etc.

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Mats