I hope the OP can go here and see this, but I am currently in Vietnam as well. I am a CS student studying aboard in the US, but I was born and raised in Vietnam. I am currently on vacation. Hope we can get in touch :)
And yes, I can confirm these education is true. However, the level of the last problem was taught to very few chosen gifted student in a very limited selected school. I do remember me learning about matrix, dynamic programing, graph theory, various pascal optimization for quicker run. The rule was, if you program run more than 1s, you're out(except stated otherwise).
I'm not sure (primarily because I can't see the images) but that sounds like a basic flood fill question doesn't it? Does everyone in Vietnam do competitive algorithmic programming? (That sounds like what you're describing.) That's really interesting, because where I'm from that's typically taken only on interest, and there aren't that many interested.
I studied at Ha Noi University of Science, High School for Gifted Students and I can confirmed about algorithmic programming part. People consider math/algorithmic stuff is a major skill for CS; without it, do not even consider going CS major.
And yes, I can confirm these education is true. However, the level of the last problem was taught to very few chosen gifted student in a very limited selected school. I do remember me learning about matrix, dynamic programing, graph theory, various pascal optimization for quicker run. The rule was, if you program run more than 1s, you're out(except stated otherwise).