题目大意:从一个\(m \times n\)的格子左上角走到右下角，每个格子有一个非负整数，只能向右或者向下走，要找到一条路径使得格子里的数字的和最小？

This is an introduction to the Wall Street News Counts.

很早以前学运筹学的时候学过动态规划。最近看题目的时候看到这个名字，借助zhihu上的一篇文章，重新温习一下。

总结了一些网上的资料，比较深度搜索，回溯法和递归，以及怎么用来解决问题。

Modification of the previous question.

Useful links from stackoverflow to solve the errors when pickle for multiprocessing

Got some random walk questions from my friend. We may see lots of similar questions in stochastic process. Here is the question.

An interesting question from my friend. We may see lots of similar questions in stochastic process. Here is one question.