It's been quite a while since I systematically studied algorithms. In practice, I often use libraries or frameworks, so I have fewer and fewer opportunities to directly contemplate and implement algorithms. This lecture allowed me to reorganize from the basics. In particular, I was impressed that it not only explained the concepts but also covered the way of thinking and approaches to solving problems in detail. Thanks to this, I was able to not only recall the concepts I had forgotten, but also regain the habit of thinking about how to write more efficient code. I think algorithms are not just for coding tests, but also greatly help to improve problem-solving skills. After building my basics through this lecture, I feel more confident in approaching new problems in the future. I highly recommend it to those who want to review from the basics!