Python 程序查找 1 - n 范围内的所有素数

Question

Hi I know there are lots of solutions to this problem but I wanted some help finding out why my answer is wrong.

Here's my answer:

number = int(input("enter a number: "))

for n in range(2, number + 1):
    for i in range(2, number // 2):
        if n == 2:
            print(n)
        elif n % i == 0:
            break
        else:
            print(n)

Here's the output on my terminal:

> enter a number: 12 
  2 2 2 2 3 5 5 5 7 7 7 7 9 11 11 11 11

thankss

Answer 1

The problem with your solution is that you haven't set up the inner loop properly. The other problem (the lesser one in my opinion) is that the print is inside of your inner loop which causes the multiple prints.

Here is a proper solution:

for n in range(2, number + 1):
    isPrime = True
    for i in range(2, n - 1):
        if n % i == 0:
            isPrime = False
    if isPrime:
        print(n)

Answer 2

thanks everyone i realised i made a lot of really silly mistakes.

i fixed my code in case anyone else sees this question and wants a solution:

number = int(input("enter the number: "))

for n in range(2, number + 1):
    for i in range(2, n):
        if n % i == 0:
            break
    else:
        print(n)