The lecture itself is very good, but it is not a suitable lecture for those who are new to data structures. It assumes that you already know data structures and the C language, and covers the contents of integrating them with open source (this lecture is based on the Linux kernel). The appropriate level for listening is the level where you can implement lists and trees in the C language on your own from scratch without any help. And.. the reason why I took off 1 star is that.. the keyboard sound is as loud as the voice. This is a huge factor that breaks the concentration of the lecture. The keyboard sound is transmitted through the earphones, so my ears were sore while listening to the lecture.