用python找到emrips，我做错了什么？


finding emrips with python, what am i doing wrong?

An Emirp is a prime number whose reversal is also a prime. For
example, 17 is a prime and 71 is a prime, so 17 and 71 are emirps.
Write a program that prints out the first N emirps, five on each line.

Calculate the first N emirp (prime, spelled backwards) numbers, where
N is a positive number that the user provides as input.

Implementation Details

You are required to make use of 2 functions (which you must write).

isPrime(value) # Returns true if value is a prime number. reverse
(value) # Returns the reverse of the value (i.e. if value is 35,
returns 53). You should use these functions in conjunction with logic
in your main part of the program, to perform the computation of N
emirps and print them out according to the screenshot below.

The general outline for your program would be as follows:

Step 1: Ask user for positive number (input validation) Step 2:
Initialize a variable Test to 2 Step 3: While # emirps found is less
than the input:
Call isPrime with Test, and call it again with reverse(Test).
If both are prime, print and increment number of emirps found. Test++ Hint - to reverse the number, turn it into a string and then
reverse the string. Then turn it back into an int!

号

我的代码：

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n = 0
count = 0
i = 1
def isPrime(value):
    test = 2
    count = 0
    while(test < value):
        if( value % test == 0):
            count+=count
            test+=test
    if(count == 0):
        return 1
    else:
        return 0

def reverse(value):
    reverse = 0
    while(value > 0):
        reverse = reverse * 10 + (value % 10)
        value = value / 10
    return reverse

n = float(input("Please enter a positive number:"))

while(count < n):
    i+=i;
    if(isPrime(i)):
        if(isPrime(reverse(i))):
                print("i" +"
")
                count+=count
        if((count % (5)) == 0 ):
                print("
")

错误在哪里？

已更新代码但仍不运行：

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    n = 0
    count = 0
    i = 1
    def isPrime(value):
     test = 2
    while(test < value):
        if( value % test != 0):
            test +=1
        else:
            return 0

def reverse(value):
    return int(str(value)[::-1])

i = int(input("Please enter a positive number:"))
count = 0
while(count < 5):
    if(isPrime(i)):
        if(isPrime(reverse(i))):
                print(str(i) +"
")
                count += 1
                i += 1
        else:
            i += 1
    else:
        i +=1

号

相关讨论

您的代码有很多问题。我改变了函数isPrime。除此之外，这里不需要count，如果您想通过1增加test，每个循环都使用test +=1：

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def isPrime(value):
test = 2
while(test < value):
    if( value % test != 0):
        test +=1
    else:
        return 0
return 1

有一种简单的方法可以使value字符串颠倒，并将其转换为整数：

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def reverse(value):
    return int(str(value)[::-1])

号

您必须将输入分配给i。代码中的n是一个常量5。在任何情况下，您都必须将i增加一个，如果i只是一个emirp，则必须将计数增加一个：

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i = int(input("Please enter a positive number:"))
count = 0
while(count < 5):  
    if(isPrime(i)):
        if(isPrime(reverse(i))):
                print(str(i) +"
")
                count += 1
                i += 1
        else:
            i += 1
    else:
        i +=1
相关讨论