javascript笛卡爾積演算法實作方法_javascript技巧

//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;
      }
    }
  }
}