Merge pull request #1 from Syeoryn/master

Use src/huffman.js in demo
AlgorithmsMeetup · Oct 29, 2015 · 3c022ca · 3c022ca
2 parents 08feb3e + fa4f1ac
commit 3c022ca
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Showing 2 changed files with 5 additions and 89 deletions.
diff --git a/Demo.html b/Demo.html
@@ -4,6 +4,7 @@
   <script src="lib/jquery.js"></script>
   <script src="src/priorityQueue.js"></script>
   <script src="src/misc.js"></script>
+  <script src="src/huffman.js"></script>
 </head>
 <body>
   <div class='column c1'>
@@ -107,92 +108,6 @@ <h2>Efficiency:</h2>
     }
   </style>
   <script>
-    var countChars = function(input) {
-      var counts = {};
-      for (var i = 0; i < input.length; i++) {
-        var c = input[i];
-        counts[c] = counts[c] || 0;
-        counts[c]++;
-      }
-      return counts;
-    };
-
-    var makeHuffmanTree = function(input) {
-      var charCounts = countChars(input);
-      var pq = new PriorityQueue();
-
-      for (var c in charCounts) {
-        var n = charCounts[c];
-        var tree = new Tree([c]);
-        pq.insert(n, tree);
-      }
-
-      while (pq.size() > 1) {
-        var first = pq.extract();
-        var second = pq.extract();
-
-        var tree1 = first.val;
-        var tree2 = second.val;
-
-        var key1 = first.key;
-        var key2 = second.key;
-
-        var newTree = new Tree(tree1.val.concat(tree2.val));
-        newTree.left = tree1;
-        newTree.right = tree2;
-        pq.insert(key1+key2, newTree);
-      }
-
-      return pq.extract().val;
-    };
-
-    var encodeChar = function(c, huffman) {
-      var output = "";
-      while (huffman.val.length > 1) {
-        if (huffman.left.val.indexOf(c) !== -1) {
-          huffman = huffman.left;
-          output += "0";
-        } else if (huffman.right.val.indexOf(c) !== -1) {
-          huffman = huffman.right;
-          output += "1";
-        } else {
-          throw new Error("Character " + c + " is not in this Huffman tree.");
-        }
-      }
-      return output;
-    };
-
-    var encodeString = function(input, huffman) {
-      var output = "";
-      for (var i = 0; i < input.length; i++) {
-        output += encodeChar(input[i], huffman);
-      }
-      return output;
-    };
-
-    var decodeString = function(input, huffman) {
-      var output = "";
-      var currNode = huffman;
-      for (var currIdx = 0; currIdx < input.length; currIdx++) {
-        var currBit = input[currIdx];
-        if (currBit === "0") {
-          currNode = currNode.left;
-        } else if (currBit === "1") {
-          currNode = currNode.right;
-        } else {
-          throw new Error("String to decode must consist of only 0s and 1s.");
-        }
-        if (currNode.val.length === 1) {
-          output += currNode.val[0];
-          currNode = huffman;
-        }
-      }
-      if (currNode !== huffman) {
-        throw new Error("String cannot be decoded - make sure you aren't missing any bits!");
-      }
-      return output;
-    };
-
     var getDictionaryFromTree = function(tree) {
       var result = {};
 
@@ -315,4 +230,4 @@ <h2>Efficiency:</h2>
 
   </script>
 </body>
-</html>
+</html>
diff --git a/src/huffman.js b/src/huffman.js
@@ -1,13 +1,13 @@
 // // Given a Huffman tree and a string, encode that string into a new string
 // // consisting only of 1s and 0s, using the code given by the tree.
 var encodeString = function(input, huffmanTree) {
-  return "";
+  return "Not implemented yet!";
 };
 
 // // Given a Huffman tree and a string of 1s and 0s, decode that string into
 // // a new, human-readable string, using the code given by the tree.
 var decodeString = function(input, huffmanTree) {
-  return "";
+  return "Not implemented yet!";
 };
 
 // Given a corpus of text, return a Huffman tree that represents the
@@ -22,6 +22,7 @@ var decodeString = function(input, huffmanTree) {
 // You may also use the `Tree` class that is provided in the file `misc.js`
 // Some corpuses are included as the variables `lorumIpsum` and `declaration`.
 var makeHuffmanTree = function(corpus) {
+  alert("You must implement makeHuffmanTree first!")
   return new Tree();
 };