HackerRank Python if-else题目代码问题：偶数大于20判断失效求助

Hey there! Let's break down why your final elif branch isn't working, and fix it up step by step.

The Core Issue #

Your problem comes from using range(6,20) and range(2,5) directly in your conditional checks. In Python, a range object is always considered "truthy" (evaluates to True) in a boolean context—even if the range doesn't include your number! So when you write num == 0 and range(6,20), this condition will always be True for any even number, because the range part doesn't actually check if N is inside that range. That means any even number ≥6 will trigger the second elif branch, even if it's greater than 20—so your final branch never gets a chance to run.

Fixed Code #

Here's the corrected version that follows the problem's logic properly:

if __name__ == '__main__':
    N = int(input())
    num = N % 2
    if num > 0:
        print("Weird")
    elif num == 0 and 2 <= N <= 5:
        print("Not Weird")
    elif num == 0 and 6 <= N <= 20:
        print("Weird")
    elif num == 0 and N > 20:
        print("Not Weird")

What Changed? #

• Replaced range(2,5) with 2 <= N <=5: This explicitly checks if N falls between 2 and 5 (inclusive), which matches the problem's requirement for even numbers in that range to be "Not Weird".
• Replaced range(6,20) with 6 <= N <=20: This correctly checks if N is between 6 and 20 (inclusive), covering the even numbers that should be labeled "Weird".
• Now, when N is an even number greater than 20, it will skip all previous branches and hit the final elif, printing "Not Weird" as expected.

Alternatively, you could use N in range(2,6) for the 2-5 check (since range(2,6) includes 2,3,4,5) and N in range(6,21) for 6-20 (since range(6,21) goes up to 20), but using direct comparison is often more readable for simple ranges like this.

内容的提问来源于stack exchange，提问作者Mittnick