• JavaScript 上万关键字瞬间匹配 (转 整理)


    ;(function (window, document, ns, undefined) {
        var Node = function  (data, parentNode) {
            this._childCount = 0;
            this.data = data;
            this.parentNode = parentNode || null;
            this.childNodes = {};
        };
        Node.prototype = {
            constuctor : Node,
            appendChild : function  (data) {
                var child;
                if(!(child = this.getChild(data))){
                    child = new Node(data, this);
                    this.childNodes[data] = child;
                    this._childCount ++;
                }
                return child;
            },
            getChild : function  (data) {
                if(this.childNodes.hasOwnProperty(data)){
                    return this.childNodes[data];
                }
                return null;
            },
            removeChild : function  (data) {
                var child;
                if(child = this.getChild(data)){
                    delete this.childNodes[data];
                    this._childCount-- ;
                }
                return child;
            },
            clearChild : function  () {
                this.childNodes = {};
                this._childCount = 0;
                return this;
            },
            hasChild : function  (data) {
                if(!this._childCount){
                    return false;
                }
                if(arguments.length > 0){
                    for (var i = arguments.length; i--; ){
                        if(!this.getChild(arguments[i])){
                            return false;
                        }
                    }
                    return true;
                }
                return true;
            }
        };
     
        var TrieTree = function (aData) {
            var maxLength = 0;
            var currentStr;
            var currentChar;
            var root = new Node('');
            var currentNode;
            var childNode;
            for (var i = 0, l = aData.length; i < l; i++) {
                if(!(currentStr = aData[i])){
                    continue;
                }
                currentNode = root;
     
                for (var j = 0, li = currentStr.length; j < li; j++ ){
                    currentChar = currentStr.charAt(j);
                    childNode = currentNode.getChild(currentChar);
                    if(!childNode){
                        childNode = currentNode.appendChild(currentChar);
                    }
     
                    currentNode = childNode;
                }
            };
     
            this._root  = root;
     
        };   
     
        TrieTree.prototype = {
            constuctor : TrieTree,
            exactMatch : function  (str) {
                var currentNode = this._root;
                var childNode;
                for (var i = 0, l = str.length; i < l; i++){
                    childNode = currentNode.getChild(str.charAt(i));
                    if(!childNode){
                        return false;
                    }
                    currentNode = childNode;
                }
                if(currentNode.hasChild()){
                    return false;
                }
                return true;
            },
            mmFetch : function (str) {
                var currentNode = this._root;
                var childNode;
                for (var i = 0, l = str.length; i < l; i++){
                    childNode = currentNode.getChild(str.charAt(i));
                    if(!childNode){
                        return false;
                    }
                    currentNode = childNode;
                }
                return true;
            }
        };
     
        ns.TrieTree = TrieTree;
     
    }(window, document, window));
     
     
     
     
    /*
        test case
        var dataSource = [
              '你好么',
              '你好呀',
              '你吃了么',
              '中国',
              '中南海',
              '中心思想',
              '上海',
              '上海人',
              '上证指数',
              '上海滩',
              '北京',
              '北京人',
              '北京你好',
              '北京猿人',
              '北京人在纽约'
          ];
          var tt  = new TrieTree(dataSource);
          document.write('<h1>数据源 : </h1></br>', dataSource.join('</br>'))
     
     
          var str = '上海滩';
          console.log(str, '
    前缀匹配 : ' + tt.mmFetch(str), '
    完全匹配 : ' + tt.exactMatch(str));
    var treeSearch = {
        makeTree: function(strKeys) {
            "use strict";
            var tblCur = {},
                tblRoot,
                key,
                str_key,
                Length,
                j,
                i
                ;
            tblRoot = tblCur;
            for ( j = strKeys.length - 1; j >= 0; j -= 1) {
                str_key = strKeys[j];
                Length = str_key.length;
                for ( i = 0; i < Length; i += 1) {
                    key = str_key.charAt(i);
                    if (tblCur.hasOwnProperty(key)) { //生成子节点
                        tblCur = tblCur[key];
                    } else {
                        tblCur = tblCur[key] = {};
                    }
                }
                tblCur.end = true; //最后一个关键字没有分割符
                tblCur = tblRoot;
            }
            return tblRoot;
        },
        search: function(content, tblRoot) {
            "use strict";
            var tblCur,
                p_star = 0,
                n = content.length,
                p_end,
                match,  //是否找到匹配
                match_key,
                match_str,
                arrMatch = [],  //存储结果
                arrLength = 0   //arrMatch的长度索引
                ;
     
            while (p_star < n) {
                tblCur = tblRoot; //回溯至根部
                p_end = p_star;
                match_str = "";
                match = false;
                do {
                    match_key = content.charAt(p_end);
                    if (!(tblCur = tblCur[match_key])) { //本次匹配结束
                        p_star += 1;
                        break;
                    }else{
                        match_str += match_key;
                    }
                    p_end += 1;
                    if (tblCur.end === true) //是否匹配到尾部  //找到匹配关键字
                    {
                        match = true;
                    }
                } while (true);
     
                if (match === true) { //最大匹配
                    arrMatch[arrLength] = { //增强可读性
                        key: match_str,
                        begin: p_star - 1,
                        end: p_end
                    };
                    arrLength += 1;
                    p_star = p_end;
                }
            }
            return arrMatch;
        }
    };
    function test(strContent, strKeys) {
        var arrMatch,
            tblRoot = treeSearch.makeTree(strKeys),
            t = new Date();
     
     
        arrMatch = treeSearch.search(strContent, tblRoot);
     
        console.log("time is: " + (new Date() - t) + "mm");
     
        console.log(arrMatch);
    }
    var s = (function() {
        var Things = [' ', '
    ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'];
        var s = "";
        for (var i = 1000000; i >= 0; i--) {
            s += Things[parseInt(Math.random() * Things.length) % Things.length]
        };
        return s;
    })()
    test(s, ["abc", "efge", "fun", "tree"]);

    原文:https://www.cnblogs.com/index-html/archive/2013/04/17/js_keyword_match.html

    https://www.cnblogs.com/ry123/archive/2013/04/24/3039720.html

  • 相关阅读:
    JMM、asifserial语义、happensbefore模型
    jvm内存溢出实践
    垃圾回收和GC算法
    jvm运行时数据区域
    实现加锁的消费者和生产者模型
    jvm监控工具小结
    HotSpot对象
    java常用垃圾收集器
    字面量, 符号引用与直接引用
    常用线程安全的队列
  • 原文地址:https://www.cnblogs.com/shikyoh/p/13151524.html
Copyright © 2020-2023  润新知