Hi! I’ve recorded a screencast that includes video solutions for the problems MODEFREQ, ELOMAX, ARRGAME, ALIENIN, CNTGRP, ELEVATR (50 points), and SHENQ (50 points) (meaning all of div. 2 except for full ELEVATR). The video is here and there are timestamps for everything in the description.
I try to make them as detailed as possible and mix in implementation details with solution ideas, but still, feel free to ask questions or leave feedback if something’s unclear. As a note, these are unofficial, and will probably differ from the solutions of the real editorials.