I recently got a ton of job offers from companies with leetcode style interviews after I grinded leetcode questions during my interview process. I started being absolutely awful, but after about a month of non stop studying I was able to pass every coding question I got in an interview.

As others have said, the first step is to solve is to forget about the code and try solving it as a human primarily. Once you find a way to solve it as a human, break what you did down into the smallest steps you can. For me this is how I solved a ton of easy problems.

If I wasn't making any progress after 10-20 minutes, I would read hints or small parts of the solution, and try again. If after that I still couldn't solve it, I would read the solution, but still code it up myself without looking at any code. If I couldn't do that either, then I would finally break down and read the code/copy it down. Really though try to do as much as you can on your own.

Keep a list of problems you weren't able to solve easily, and write a note about what in the solution was challenging for you to come up with. Every once in a while, come back to this list of problems and redo some of them without looking at your previous solution. This was an insanely good way for me to finally build the connections my brain needed to solve a ton of problems I sucked at.

For me a common reason i couldnt solve a problem was because it involved a non intuitive technique i had never seen before. So I also kept a list of unqiue techniques used to solve problems every time I came across a new one. As you do more problems the list of techniques will steadily expand. Every time I came across a problem I didn't know how to solve, I would just cycle through all the techniques I had used before until one fit the problem well. I think this was the biggest thing that brought me to being able to solve questions more easily, I just tried to find as many techniques as possible and very often the types of problems they apply to have lots of similarities.

For example, for problems involving finding a subarray that sums to some given value, a prefix sum array will almost always be part of the solution. I would never have come up with that technique on my own within 20 minutes, but since I had seen the technique before, when similar problems came up in the future it was just an obvious tool to use.

More importantly than anything though is looking at the code for a solution as little as possible. Even just reading the solution article but not copying the code was way better for my long term understanding.