How do you fell about constructive problems?

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Recently I've been seeing more and more constructive problems and I was wondering if that is a good or a bad thing.

Firstly what problems are included in the type of constructive. They are the ones that require you to come up with a solution to satisfy some constraint. Usually there is no hint in the statement for how to do that and often the solution comes by trying a bunch of random things. This definition is very vague so I think to form a better idea we should look at some examples.

Before that I must say why I think they are invaluable and why I like them so much. Because they show what the human brain is capable of, and unleashes it's creativity because they don't involve any standard algorithm. By solving a lot of them you will improve your pattern recognition which will help in a lot of different areas.

Now some problems with 1400 — 1600 difficulty

I really liked the solution to this problem: https://mirror.codeforces.com/problemset/problem/1517/C

Spoiler

I think interactives are inherently constructives: https://mirror.codeforces.com/contest/1698/problem/D

Spoiler

These were all the problems I could think of right now.

Feel free to suggest some nice constructive problems and also don't forget to say if you either like or hate this type tasks. (I think there is no in between)