Question

我写了下面的代码来找出乘法的数字根和乘法的持久性。我对乘法数字根很清楚，但对乘法持久性（MP）有疑问。

在下面的代码中，有两个while循环，并且为了发现MP每次累加时都会增加一个计数器。

当内部count += 1行包含在内部while循环中并且保留在外部while循环中时，MP有所不同。

count += 1在外部循环中时的输出为222 : [8, 3]

现在我的问题是对于多重复制持久性是正确的。

已引用https://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root，并且根据此count += 1在外部循环中，输出为222 : [8, 1]

任何人都可以建议哪个是正确的吗？

    def mdr_mp(num):
    '''
    This function computes the multiplicative digital root and multiplicative persistence of a given number
    '''
    product = 1
    mdr = num
    count = 0

    #Find mdr and persistence 
    while mdr > 9: #as long as mdr is > 9 
        while num > 0: #as long as quotient is > 0 
            #use divmod fn to return the quotient and remainder of num when divided by 10
            num, number = divmod(num, 10)
            product *= number #perform product of each digit in the number
            count += 1
        mdr = product #set product to mdr so as to check if it is > 9 else repeat
        num = product #set product to num so as to perform the product again
        product = 1 #initialize product to 1 so that product of the new num can be computed
        #count += 1 #multiplicative persistence 

    return [mdr, count] #returns multiplicative digital root and multiplicative persistence as a list

    num = 222
    #Function call returns list of number containing mdr and mp
    print("Number: (MDR, MP)")
    list1 = mdr_mp(num)
    print(num, ": ", list1)

Output:
    Number: (MDR, MP)
    222 :  [8, 3]

Answer 1

对于222，(mdr, mp)是(8, 1)。 -> 2 * 2 * 2 = 8个循环。

对于34，(mdr, mp)是(2, 2)。 -> 3 * 4 =12。1* 2 =2。在2个循环中完成。

以编程方式：

def get_mdr_and_mp(number):
    time_multiplied = 0
    current_mdr = number
    while current_mdr > 9:
        current_mdr = multiply_all_digits(current_mdr)
        times_multiplied += 1
    return current_mdr, times_multiplied

Answer 2

这里是另一种简化的代码形式：

 def mula(a):
        mul=1
        for i in str(a):
            mul=mul*int(i)
        mul+=1
        return (mul-1)

    c=int(input("Enter a number"))

    cnt=0
    while c>=10:
        c=mula(c)
        cnt+=1
    print("MDR:{}  MPer:{}".format(c,cnt))

乘法数字根和乘法持久性

2 个答案: