素数，埃拉托色尼筛法，Python

Question

我正在开发一个程序，该程序在用户输入最大整数时在一个范围内打印可能的素数列表。基本上是Erasthothenes的筛子。

现在，这个代码块应该迭代 consecInt（一个存储 2 到该最高整数的列表的变量）的所有值并删除它们的倍数。但由于某种原因我不太明白，它只适用于第一个值。

print("                 Sieve of Erasthothenes\n    Program that generates the possible prime numbers within a given range")

n = int(input("\nEnter the highest range:   "))

def primeList(n):

    j = 2
   consecInt = [int(i) for i in range(2, n+1)]

#A = [i != False for i in range(2, n+1)]

    for i in consecInt:
        p = i
        while j <= n:
            c = j*p
            if c <= n:
                consecInt.remove(c)
             j+=1

    print(consecInt)

primeList(n)

Answer 1

您应该在 for 循环的每次迭代中将 j 重置为 2。除此之外，还有其他几个错误。

def primeList(n):
    consecInt = [int(i) for i in range(2, n+1)]

    for i in consecInt:
        j = 2      ## reset `j` to 2 at every iteration
        while j*i <= n:   ## it is sufficient to check `j*i <= n` rather than `j <= n`
            c = j*i

            if c in consecInt:    ## if `c` is NOT in consecInt, a ValueError will be raised
                consecInt.remove(c)

            j += 1

    print(consecInt)

primeList(n)