Question

如果各个数字的阶乘的总和等于数字本身，则数字是强数字。例如：145 = 1！ + 4！ 5！

我在python中为此编写了以下代码：

import math
def strong_num():
    return [x for x in range(1,1000) if x==int(reduce(lambda p,q:math.factorial(int(p))+math.factorial(int(q)),str(x)))]

print strong_num()

但是翻译永远不会回来？这段代码有什么问题？

Answer 1

您的reduce输入错误，您不应计算p的阶乘。事实上，使用sum：

更容易

return [x for x in range(1, 1000) 
          if x == sum(math.factorial(int(q)) for q in str(x))]

functools.reduce功能可视为：

reduce(f, [a, b, c, d, ...]) == f(f(f(a, b), c), d) ...

因此，例如，如果x == 145，那么您的reduce部分将计算

   int(reduce(lambda p, q: factorial(int(p)) + factorial(int(q)), str(x)))
== int(reduce(lambda p, q: factorial(int(p)) + factorial(int(q)), "145"))
== int(factorial(factorial(1) + factorial(4)) + factorial(5))
== int(factorial(1 + 24) + 120)
== int(15511210043330985984000000 + 120)
== 15511210043330985984000120

解释器无法完成，因为需要计算极大数的阶乘（考虑（2×9！）！...）

如果您仍需要保留reduce，则应将其更改为：

 reduce(lambda p,q: p + math.factorial(int(q)),  str(x),  0)
#                   ^                                     ^
#                   No need to factorial                  Add initializer too

Answer 2

什么是强数？

强数是那些数字的阶乘之和等于原始数字的数字。 例如： 145是强数。从1开始！ + 4！ + 5！ = 145

num = int(input("Enter any number"))
user_given_no=num
i = 0
fact = 1
fact_list = []
diff_no = []
while num != 0:
    i = num % 10
    num = num//10
    diff_no.append(i)


for y in diff_no:

    x = y
    fact = 1
    while x != 0:
        fact *= x

        x -= 1
    fact_list.append(fact)

sum = 0
for x in fact_list:
    sum += x

if sum == user_given_no:
    print("Strong number")
else:
   print("Not a Strong number")

Answer 3

强数是那些数字的阶乘和等于原始数的数字。 因此，这里有一个简单的程序可以在python列表中找到强数。

def factorial(number):
    if(number == 0 or number == 1):
        fact = 1
    else:
        fact = number * factorial(number - 1)
    return fact

def strong_number(list):
    new_list=[]
    for x in list:
        temp = x
        sum = 0
        while(temp):
            rem = temp % 10
            sum += factorial(rem)
            temp = temp // 10
        if(sum == x):
           new_list.append(x)
        else:
           pass  
    return new_list

# Example 1
val_list = [1,2,5,145,654,34]
strong_num_list = strong_number(val_list)
print(strong_num_list)
# Example 2 and this will return an empty list as there is no strong number found in 
the list that is passed
val_list2 = [5,10,14,34,45]
strong_num_list = strong_number(val_list2)
print(strong_num_list)

现在，如果您不想传递列表，则只需从strong_number函数中删除for循环即可。学习愉快！

Answer 4

import math
x=(input("enter the number\n"))

y=[int(i) for i in x]
#print("digits of the entered number:\n",y)

z=list((math.factorial(i) for i in y))
#print("factorial of each digit of given number:\n",z)

z=sum(z)
#print("sum of factorials of each digit of the given number:\n",z)


if z==int(x): print(x,"is a Strong Number")
else: print(x,"is not a Strong Number ")

Answer 5

您没有正确地将数字分解为其组成数字。你需要reduce来在整数列表上运行lambda，而str（x）不会产生整数列表。

python中的强数字

5 个答案: