# Spawn-Failed

Recently, I’ve met a problem like this when I deploying my blog. hexo d gets error.

When this occurs, usually you just need to deploy it again in good internet condition. This is just your internet doesn’t work well, at least for me always.

# CodeForces-1293B JOE is on TV!

B. JOE is on TV!

time limit per test: 1 second

memory limit per test: 256 megabytes

input: standard input

output:standard output

# CodeForces-1293A ConneR and the A.R.C. Markland-N

A. ConneR and the A.R.C. Markland-N

time limit per test: 1 second

memory limit per test: 256 megabytes

input: standard input

output: standard output

# Sorts

Here are some sorting ways and I use many data to test and compare. Just to illustrate the property of each algorithm.

# CodeForces-1288 B Yet Another Meme Problem

B. Yet Another Meme Problem

time limit per test:1 seconds

memory limit per test:256 megabytes

input: standard input

output: standard output

time limit per test:2 seconds

memory limit per test:256 megabytes

input: standard input

output: standard output

# Mathematical Statistics Concepts

（1）总体与个体

​ a. 一批灯泡的全体组成一个总体，其中每一个灯泡都是一个个体。

​ b. 一个随机变量X或其相应的分布函数$F(x)$成为一个总体。

# Law of Large Numbers

（1）切比雪夫不等式

​ $X$有数学期望$E(X)=\mu,D(X=\sigma^2)$, 则对任意正整数$\varepsilon$

​ $P{\left| x - \mu \right| \geq \varepsilon } \leq \frac{\sigma ^2}{\varepsilon ^ 2}$

​ $P{\left| x - \mu \right| < \varepsilon } \geq 1-\frac{\sigma ^2}{\varepsilon ^ 2}$

1. 离散型

# Story of Cow

There is a cow that gives birth to a heifer at the beginning of each year. Each heifer starts in the fourth year and a heifer is born at the beginning of each year. Please program how many cows will there be in year n?