[weekly pit] calculate the sum of primes within 100 + [answer] output triangle

Zero basis python Introductory tutorial ：python666.cn

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Today's topic is very short ：

Calculation 1 To 100 The sum of all prime numbers within

The so-called prime number , Except 1 And the number itself , A number that is not divided by other natural numbers .

1. To judge whether a number is a prime number , This is not difficult
   

2. find 1~100 Within the scope of , All prime numbers , This is very simple
   

3. Add up the found prime numbers , This is even less difficult

Top up 3 Step together OK La ！

But if you are interested , You can further consider the algorithm complexity of your method , See whose method is simpler .

in addition , For this question , I have an interesting solution , Not exactly according to the above idea , To be announced next week .（ I don't know if anyone's answer will be the same as I think ）

Detailed answers and reference codes will be given in the next column , You can also refer to the code in the message of other students .

I look forward to your answers , I hope you can complete the whole series .

Simple code can be submitted directly in the message , Long code is recommended  paste.ubuntu.com  or  

codeshare.io  And other code sharing sites , Just copy the code and save it , You can get a share address , Very convenient .

For past questions, click the collection at the beginning of the article “ Every Monday ” Enter the view .

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【 answer 】 Output triangle

The key to this problem is to calculate well The number of spaces in each line And The current number of lines Correspondence of .

Output multiple spaces , You can go through the loop , It can also be directly passed through “ String multiplication ” Realization , namely ：

' Original string ' * n

You can get n individual  ' Original string ' New string composed of .

Refer to the answer ：（ come from @KE10）

def ntriangle(n):
    print('*'*n)
    n -= 1
    while n > 1:
        print('*'+' '*(n-2)+'*')
        n -= 1
    print('*')


ntriangle(5)

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