Link to problem : Assimilation IV
I found this question really interesting and wanted to share a detailed approach. If you want to see the code, you can check my submissions.
I wrote this in Latex for convenience.
Please download the pdf from here: https://drive.google.com/file/d/14N5XzKPkdvMzjj4sDSohj2IITfR4V52_/view?usp=sharing