My cousin wants me to teach him more about Dynamic Programming to prepare for future CP competitions.

I have had lots of experience with competitive programming, but when asked to teach him, my mind goes blank and I can't come up with a propper roadmap to teach him. He also has the basics of competitive programming down, and he wants me to teach him some intermediate to advanced stuff.

He decided to focus on DP first, and asked me for some documents and problems to solve.

Can you please provide some useful DP techniques, optimizations and some example problems with varying difficulties?

I appreciate all of your help!

given a array of size 2e5, count how many subarrays where theres an element that appears more than half of the subarray's size