約分できない真分数を加算するので、分数が分母の素因数の倍数の場合は、加算されないことになる。 2022に三つの素因数がある。2と3と337である。つまり、$U=\{1,2,3,…,2021\}$の中に、2の倍数でもなく、3の倍数でもなく、337の倍数でもない数字がどのくらいあるかを数える問題になる。式を書きやすくするために、記号を定義する。$U$の中の2の倍数の集合を$A$となる。$U$の中の3の倍数の集合を$B$となる。Uの中の337の倍数の集合を$C$となる。すると、求めたい数は$|U|-|A \cup B \cup C|$。 $$\begin{align}|A|&=\lfloor 2021 \div 2 \rfloor = 1010 \\|B|&=\lfloor 2021 \div 3 \rfloor = 673 \\|C|&=\lfloor 2021 \div 337.
Read MoreThe sigmoid function frequently appears in machine learning contexts. It has a simple form: $$\sigma(x)=\frac{1}{1+e^{-x}}$$. A naive implementation in C would be: It looks.
Read MoreIt was said that GDB 11 or above does not work well with Eclipse with Cygwin. The true reason seems to be that Eclipse.
Read MoreExplain The Idea Word vector is widely used in text-related AI processes. Its center idea is to maximize the following likelihood function. $$\begin{equation} \label{eq:originalL}L(\theta).
Read MoreReact-Native claims to let people write once and run everywhere. So today, I decided to have it at my PC. And I don’t want.
Read MorePowershell has many cmdlets that help users perform various tasks. In this post, I will use several commands to collect CPU and memory usage.
Read MoreThe following command lists all counter sets. The result on my PC (Windows 10) is the following: Wish this helpful!
Read MoreIt has been a year perhaps? I lost my sites. Now it’s about time to start anew. With this simple post, I just try.
Read More