In the past, I studied development by simply focusing on implementation, and I couldn't solve a single algorithm problem. However, now, I have internalized the basic algorithms and codes to the point where I can estimate the time complexity by eye, and when I write code myself, I find it fun to apply various algorithms and optimize them, rather than just implementing them. For those who have been focusing on implementation like me, I think this is a good lecture that will help them grow one step further.