Tomoharu TsutsumiTried a design problem of Amazon’s sales rank by category featureI tried this problem. I could learn some points and summarize them.2 min read·Mar 16, 2024----

Tomoharu TsutsumiImproved an algorithm from O(n log n) to O(m + n)Recently, I’ve started reviewing algorithm problems I did in the past in order to find better solutions.1 min read·Mar 3, 2024----

Tomoharu TsutsumiInstead of splice, use swap and pop【JavaScript】Hi, I’ve been immersed in leetcoding. Especially, I’m spending a lot of time improving bad code I wrote before. Today, I could improve…1 min read·Feb 25, 2024----

Tomoharu TsutsumiNot O(N²), but O(log N)When I saw this algorithm below at first, I thought the time of complexity was O(N²). However, it is O(log N). I’ll explain it.2 min read·Feb 11, 2024----

Tomoharu TsutsumiHow to make a habit of studyingStudying takes us much time. In particular, I’m a software engineer, which requires tons of knowledge. Besides, I have to learn English…2 min read·Feb 3, 2024----

Tomoharu TsutsumiTackled a problem of developing a web crawler architectureHi, architects. I learned a new problem of architecture and summarized what point was good and bad.2 min read·Jan 27, 2024----

Tomoharu TsutsumiHow to avoid O(N²)Hi, algorithm aficionados! Recently, I’ve started learning algorithms and found some patterns of making them faster. I’ll share one of them…4 min read·Jan 20, 2024----

Tomoharu TsutsumiTackled a system architecture problem of Twitter(X)I solved the system architecture problem of Twitter(X). There were many points I improved, so I’ll summarize them.2 min read·Jan 13, 2024----

Tomoharu TsutsumiCareful approach to understand why the best time complexity of quick sort is O(N logN) and worst…The best time complexity of quick sort is O(N logN), but how can we get it? Some people are just memorizing it, but we need to understand…5 min read·Jan 6, 2024----