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我重新设计了程序以获得大素数。现在它工作正常，除了在打印所有输出之后我最后得到大量红色短语。有人可以告诉我为什么吗？

输出的结尾是：

(100000939.0, 'is prime')
(100000963.0, 'is prime')
(100000969.0, 'is prime')

错误是

Traceback (most recent call last):
  File "C:/Users/Marcela/Documents/Prime numbers to 100", line 48, in <module>
    loopfunction()
  File "C:/Users/Marcela/Documents/Prime numbers to 100", line 35, in loopfunction
    loopfunction()
  File "C:/Users/Marcela/Documents/Prime numbers to 100", line 35, in loopfunction
    loopfunction()
  File "C:/Users/Marcela/Documents/Prime numbers to 100", line 35, in loopfunction
    loopfunction()
...(many lines of it, the int ends with:) 
File "C:/Users/Marcela/Documents/Prime numbers to 100", line 13, in loopfunction
    while index <= 200000000.0:
RuntimeError: maximum recursion depth exceeded in cmp

这是脚本：

from __future__ import division
import sys
index=100000000.0
checker=2.0



def loopfunction():
    global index
    global checker
    checker=2

    while index <= 200000000.0:

        if index>=200000001:
            sys.exit(1)
        while checker<=14473.0:

            div = index/checker
            roundiv=round(index/checker, 0)
            if index == 1:
                print (index, "is prime")
                checker=2
                index=index+1
                loopfunction()   
            if checker == index:
                print (index, "is prime")
                checker=2
                index=index+1
                loopfunction()
            if roundiv==div:

                checker=2
                index=index+1
                loopfunction()    

            if checker==14473.0:

                print (index, "is prime")
                checker=2
                index=index+1
                loopfunction()

            checker = checker +1



loopfunction()
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1 回答 1

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You can fix your recursion limit issue by simply not recursing. Your code already has the loops you need.

Just change the calls to loopfunction() in the various if statements to break.

While that is all that is needed to make the code function, I've noticed though that some of number of your if statements are unnecessary (either redundant with the loop conditions, or simply impossible to ever hit). You're also using while loops where for _ in range() loops would make more sense. Here's a greatly simplified version of your code, with some things renamed to clarify their purposes:

from math import sqrt

def primeFinder(start, end):
    prime = True

    for index in range(start, end):
        for checker in range(2, int(sqrt(index))+1):
            if index % checker == 0:
                prime = False
                break

        if prime:
            print("%d is prime" % index)

        prime = True

primetest(100000000, 200000001)

This version will still take a very long time (probably hours). If you really want to test a hundred million values for primeness, you should probably investigate a better algorithm, such as the Sieve of Eratosthenes.

于 2012-06-17T00:54:34.243 回答