JS笛卡尔积算法与多重数组笛卡尔积实现方法示例

//笛卡儿积组合function descartes(list) {  //parent上一级索引;count指针计数  var point = {};  var result = [];  var pIndex = null;  var tempCount = 0;  var temp = [];  //根据参数列生成指针对象  for (var index in list) {    if (typeof list[index] == 'object') {      point[index] = {        'parent': pIndex,        'count': 0      }      pIndex = index;    }  }  //单维度数据结构直接返回  if (pIndex == null) {    return list;  }  //动态生成笛卡尔积  while (true) {    for (var index in list) {      tempCount = point[index]['count'];      temp.push(list[index][tempCount]);    }    //压入结果数组    result.push(temp);    temp = [];    //检查指针最大值问题    while (true) {      if (point[index]['count'] + 1 >= list[index].length) {        point[index]['count'] = 0;        pIndex = point[index]['parent'];        if (pIndex == null) {          return result;        }        //赋值parent进行再次检查        index = pIndex;      } else {        point[index]['count']++;        break;      }    }  }}

var result = descartes({'aa':['a','b','c','d'],'bb':['$','%','^','&']});alert(result);//result就是笛卡尔积

<script>(function() {  dwn = function(a) {    document.writeln(a + "<br />")  };  //笛卡尔积  var Cartesian = function(a, b) {    var ret = [];    for (var i = 0; i < a.length; i++) {      for (var j = 0; j < b.length; j++) {        ret.push(ft(a[i], b[j]));      }    }    return ret;  }  var ft = function(a, b) {    if (! (a instanceof Array)) a = [a];    var ret = Array.call(null, a);    ret.push(b);    return ret;  }  //多个一起做笛卡尔积  multiCartesian = function(data) {    var len = data.length;    if (len == 0) return [];    else if (len == 1) return data[0];    else {      var r = data[0];      for (var i = 1; i < len; i++) {        r = Cartesian(r, data[i]);      }      return r;    }  }})();var data = [['a', 'b', 'c'], [1, 2, 3, 4], ['A', 'B'], ['#', '@', '+'], ['Mary', 'Terry', 'KYO']];var r = multiCartesian(data);for (var i = 0; i < r.length; i++) {  dwn("(" + r[i] + ")");}</script>