Question

some lectures are missing , like lecture 4 and others , will they be uploaded or what ?

Answer 1

My thought on that is that for whatever reason, be it copyright or not wanting to release the whole class, they will not be available.

The Design and Analysis of Algorithms is also missing a few lectures and its years old.

Answer 2

Thankfully, only the lecture video is missing from that section. I found that the readings and recitation videos gave more than enough instruction to figure out the labs and problem sets for the section missing the lecture 4 video.