0.字体

<font face="黑体" >

</font>

1.多行对齐
![图片说明](https://www.nowcoder.com/equation?tex=%5Cbegin%7Balign*%7D%5Clabel%7B2%7D%0A%26%20f%5Bi%5D%5Bj%5D%3Df%5Bi-1%5D%5Bj-1%5D%2B1%5C%5C%0A%26%20f%5Bi%5D%5Bj%5D%3Df%5Bi-1%5D%5Bj%5D%2B1%0A%5Cend%7Balign*%7D "图片标题")

 \begin{align*}\label{2}
& f[i][j]=f[i-1][j-1]+1\\
& f[i][j]=f[i-1][j]+1
\end{align*}

2.空格
![图片说明](https://uploadfiles.nowcoder.com/images/20200408/7533514_1586349272204_0F638D465D20018896B069E14260096B "图片标题")
3.分类
图片说明%3D%0A%5Cbegin%7Bcases%7D%20%0An%2F2%2C%20%26%20%5Ctext%20%7Bif%20%24n%24%20is%20even%7D%20%5C%5C%20%0A3n%2B1%2C%20%26%20%5Ctext%7Bif%20%24n%24%20is%20odd%7D%20%0A%5Cend%7Bcases%7D "图片标题") 

 f(n)=
\begin{cases} 
n/2, \text {if $n$ is even} \\ 
3n+1, \text{if $n$ is odd} 
\end{cases}