因数分解

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。 

package main

import (

    "fmt"

    "math"

)

func divi(div int) (int, int) {

    var i int

    for i = 2; i <= int(math.Sqrt(float64(div))); i++ {

        if div%i == 0 {

            return i, div / i

        }

    }

    return 1, div

}

func main() {

    var num, temp, buf int

    fmt.Scanf("%d", &num)

    fmt.Printf("%d = ", num)

    buf = num

    for temp != 1 {

        temp, buf = divi(buf)

        if buf == num {

            fmt.Printf("%d * 1", num)

            return

        } else if temp == 1 {

            fmt.Printf("%d", buf)

        } else {

            fmt.Printf("%d * ", temp)

        }

    }

}

运行结果：

	90



	90 = 2 * 3 * 3 * 5

...

	2489



	2489 = 19 * 131

...

	45678



	45678 = 2 * 3 * 23 * 331