哈夫曼编码，根据每个单词在文本中出现的次数频率为权值，频率高的权值大。然后每次取两个频率最小的生成树，最后生成一颗大树。从根节点到该单词的路径，左边为0，右边为1,
function HFM(){var souce = [];function createNode(node){var obj = {weight:0, ?parent:-1,lchild:-1,rchild:-1,value:‘‘};return Object.assign(obj,node);}this.addNode = function(node){//添加单词和频率（权值）souce.push(createNode(node));}this.createTree = function(){//哈夫曼树var HuffNode ?= JSON.parse(JSON.stringify(souce));var n = HuffNode.length;var x1,x2; //两个权值最小的索引 var m1,m2; ????????//两个权值最小的值for(var i = 0; i < n ; i++){m1 = m2 = Infinity; ?//初始化为最大值x1 = x2 = -1; for(var j = 0; j < n+i; j++){ //寻找两个权值最小，且父节点为-1的var item = HuffNode[j];if(item.weight ?< m1 && item.parent == -1){m2 = m1;x2 = x1;m1 = item.weight;x1 = j;}else if(item.weight ?< m2 && item.parent == -1){m2 = item.weight;;x2 = j;}}if(x1 != -1 && x2 != -1){HuffNode[x1].parent = n + i; ?//更新父节点HuffNode[x2].parent = n + i;//创建一个新的节点HuffNode[n+i] = createNode({weight:m1+m2,lchild:x1,rchild:x2});}}return HuffNode;};this.getCode = function(){//哈夫曼编码var n = souce.length; var tree = this.createTree();var codes = {};for(var i = 0; i < n; i++){var p = tree[i].parent;var code = ‘‘;var c = i;while(p != -1){ ?//迭代前溯if(tree[p].lchild == c){code = 0 + code;}else{code = 1 + code;}c = p;p = tree[p].parent;}codes[ tree[i].value ] = code;console.log(tree[i].value , code);}return codes;}}var hfm = new HFM();hfm.addNode({weight:5,value:"a"});hfm.addNode({weight:32,value:"b"});hfm.addNode({weight:18,value:"c"}); ???hfm.addNode({weight:7,value:"d"});hfm.addNode({weight:25,value:"e"});hfm.addNode({weight:13,value:"f"});console.log(hfm.getCode())
js神秘的电报密码---哈弗曼编码
原文地址：https://www.cnblogs.com/muamaker/p/9401472.html