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I'm trying to count the bytes of a txt file. In order to do that I have to count the compress efficiency with Huffman encoding. I have three classes about Huffman.

In main class: 

Scanner s = new Scanner(System.in);
    // creating a priority queue q.
    // makes a min-priority queue(min-heap).
    PriorityQueue<HuffmanNode> q
            = new PriorityQueue<HuffmanNode>(count.length, new MyComparator());

    for (int i = 0; i < count.length; i++) {

        // creating a Huffman node object
        // and add it to the priority queue.
        HuffmanNode hn = new HuffmanNode();

        hn.c = alphabet[i];
        hn.data = count[i];

        hn.left = null;
        hn.right = null;

        // add functions adds
        // the huffman node to the queue.
        q.add(hn);
    }

    // create a root node
    HuffmanNode root = null;

    // Here we will extract the two minimum value
    // from the heap each time until
    // its size reduces to 1, extract until
    // all the nodes are extracted.
    while (q.size() > 1) {

        // first min extract.
        HuffmanNode x = q.peek();
        q.poll();

        // second min extarct.
        HuffmanNode y = q.peek();
        q.poll();

        // new node f which is equal
        HuffmanNode f = new HuffmanNode();

        // to the sum of the frequency of the two nodes
        // assigning values to the f node.
        f.data = x.data + y.data;
        f.c = '-';

        // first extracted node as left child.
        f.left = x;

        // second extracted node as the right child.
        f.right = y;

        // marking the f node as the root node.
        root = f;

        // add this node to the priority-queue.
        q.add(f);
    }

    // print the codes by traversing the tree
    Huffman.printCode(root, "");

Huffman class: 

public class Huffman {
// recursive function to print the
// huffman-code through the tree traversal.
// Here s is the huffman - code generated.
public static void printCode(HuffmanNode root, String s)
{
    // base case; if the left and right are null
    // then its a leaf node and we print
    // the code s generated by traversing the tree.
    if (root.left
            == null
            && root.right
            == null
            && Character.isLetter(root.c)) {

        // c is the character in the node
        System.out.println(root.c + ":" + s);

        return;
    }

    // if we go to left then add "0" to the code.
    // if we go to the right add"1" to the code.

    // recursive calls for left and
    // right sub-tree of the generated tree.
    printCode(root.left, s + "0");
    printCode(root.right, s + "1");
}

There are two more classes about setting the objects and one for the comparison of the nodes. Huffman works fine and I am taking the following result: 

t:000
c:00100
g:00101
d:0011
w:01000
u:01001
r:0101
e:011
s:1000
n:1001
h:1010
i:1011
o:1100
b:110100... //for the rest aphabet letters.

What I need is to count the bits are being showed for every letter and save them into an integer array eg t:3 o:4(...)

Any thoughts?

Michael Pnrs
  • 115
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1 Answers1

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You want to create a map of type < Character , int[] > as a private attribute of the Huffman class. Then inside your if statement's body you want put a new pair into the map, the pair being the character and the string you have. In your case that would be root.c and s.

Since it's a string you will of course need to convert it to an integer array. You can find easy ways to do that here: Converting String Array to an Integer Array.

Then you can create a method that calls the attribute (being the map) from the Huffman class, then from the map call whatever array you want.

So your Huffman class would have to become an object, with a constructor, so you would create an Huffman object then run your print code method, then grab the map from the Huffman object.

plausiblesquat
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