I participated in ABC 250 last night, and there is something really makes me sad.

I didn't solve the problem G and problem Ex, but after the contest someone told me these two problems are exactly the same as two previous problems on Codeforces.

Let's compare:

ABC250G and CF865D

ABC250Ex and CF1253F

And recently I often hear others talking about ABC that has a lot of problems are exactly the same as some old problems on Codeforces or other platforms.

Is this normal and fair enough? I know the meaning of ABC may be more educational, but it's still quite sad to hear someone say some words like ‘I find the same problem on Codeforces and got AC by learning the solution during the contest’ .

Sorry for bothering.