Added java implementation of Huffman compression #181
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june128
added
the
Implementation
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| class HuffmanTree { | ||
| private Map<String, Integer> map = new HashMap<>(); |
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I think this could use a more descriptive name
| private Map<String, Integer> map = new HashMap<>(); | ||
| private Map<String, String> codeBook = new HashMap<>(), reverseCodeBook = new HashMap<>(); | ||
| private TreeNode root; | ||
| private String s; |
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Similarly, single-letter class members are usually not a good idea
| for (int i = 0; i < s.length(); i++) { | ||
| String key = Character.toString(s.charAt(i)); | ||
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| if (!map.containsKey(key)) map.put(key, 1); |
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If the else branch has braces, so should the if
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| while (priorityQueue.size() > 1) { | ||
| TreeNode temp1 = priorityQueue.remove(); |
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left and right are probably better names here
| while (priorityQueue.size() > 1) { | ||
| TreeNode temp1 = priorityQueue.remove(); | ||
| TreeNode temp2 = priorityQueue.remove(); | ||
| TreeNode node; |
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At least merge this declaration with the line below but you could also just dopriorityQueue.add(new TreeNode(...));
| private TreeNode root; | ||
| private String s; | ||
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| public HuffmanTree(String s) { |
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You should probay use better variable names for the constructor too
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| private void traverse(TreeNode temp, String w) { |
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Once more, these argument names are not the best.
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Also, a StringBuilder would be much better here
| private void traverse(TreeNode temp, String w) { | ||
| if (temp.left == null && temp.right == null) | ||
| codeBook.put(temp.key, w); | ||
| if (temp.left != null) traverse(temp.left, w + 0); |
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I don't think you can add integers to strings. Make sure to always test if your program compiles and works before submitting a PR
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The program is compiling fine. You can add integers to string in Java. I'll use StringBuilder as you say.
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Sorry, you're right about the addition. Weird, not many languages allow that and Java's usually pretty strict (I've never seen it used in practice either)
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Yeah, I was shocked too when I first learned about it. But you are right it creates unnecessary confusion.
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| public String encode() { | ||
| traverse(root, ""); | ||
| String enc = ""; |
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A StringBuilder would be more efficoentt here
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| public String decode(String enc) { | ||
| String dec = "", key = ""; |
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Again, a StringBuilder and variable name suggestion. Since this is an educational resource I would go with encoded/decoded instead of enc/dec
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Ok, I'll change the variable names and make them more descriptive.
I've made some of the requested changes.
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Ok, done. |
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