求数字的乘积根。

定义：正整数中非0数字的乘积称为该数数字乘积。如1620的数字乘积为1*6*2=12,12的数字乘积。

定义：正整数的数字乘积根为反复取该整数的数字乘积，直到最后的数字乘积为一个数字，这个一位数字就叫该正整数的数字乘积根。

编程要求：统计10000以内，其数字乘积根分别为1到9的正整数个数。-Multiplied by the number in the root. Definition: positive integer number multiplied Africa 0 is called the number of digital product. If the product number 1620 is 1* 6* 2 = 12 and 12 number of the product. Definition: positive integer number multiplied repeatedly taken root as the product of the integer numbers, until the final product is a digital number, this number is called a digital product of the positive integers roots. Programming requirements: Statistics and less than 10,000, and its digital product roots were 1 to 9, the number of positive integers.