题目：将一个正整数分解质因数。例如：输入90,打印出90=2*3*3*5。



程序分析：对n进行分解质因数，应先找到一个最小的质数k，然后按下述步骤完成：

(1)如果这个质数恰等于n，则说明分解质因数的过程已经结束，打印出即可。

(2)如果n<>k，但n能被k整除，则应打印出k的值，并用n除以k的商,作为新的正整数你n,

　重复执行第一步。

(3)如果n不能被k整除，则用k+1作为k的值,重复执行第一步。-Topic: the prime factors of a positive integer factorization. For example: Enter 90 to print out 90 = 2* 3* 3* 5. The program Analysis: the decomposition of the prime factors of n, we should first find the smallest prime number k, and then press the following steps: (1) If the prime numbers exactly equal to n, the decomposition of the prime factors has ended, print out can be . (2) If n < >　k, n can be k divisible should print out the value of k, and n is divided by the quotient of k, as a new positive integer N, the first step executed repeatedly. (3) If n is not divisible by k, then use k+1 as the value of k is repeatedly performed the first step.