by Xiaokang Zhang | Jan 23, 2017 | Algorithm & Data Structure
Largest Rectangle in Histogram Problem Given n non-negative integers representing the histogram’s bar height where the width of each bar is 1, find the area of largest rectangle in the histogram. The following is a histogram with the width of bar of 1, and...
by Xiaokang Zhang | Jan 22, 2017 | Algorithm & Data Structure
Maximal Rectangle problem Given a 2D binary matrix filled with 0’s and 1’s, find the largest rectangle containing only 1’s and return its area. For example, given the following matrix: 1 0 1 0 0 1 0 1 1 1 1 1 1 1 1 1 0 0 1 0 Return 6. Height, left...
by Xiaokang Zhang | Jan 22, 2017 | Economics
野生大象保护的问题 考虑一下在不同地点的一种生物：野生大象和动物园的大象。野生大象因为象牙的商业价值而濒临灭绝，相反，动物园的大象却得到很好的保护。为什么同一种生物的处境相差这么大？比较一下就会发现它们的区别： 野生大象没有主人，除了政府没有人保护，但是政府的禁令难以贯彻。偷猎野生大象的人可以获得巨大利益，成本和风险却非常小。动物园的大象属于动物园，其商业价值属于动物园，因此动物园有保护的动力。 关于野生大象的保护涉及到经济学中的另一个话题：物品的排他性和竞争性。我们先了解一下这两种属性，再回来看如何解决野生大象保护的问题。...
by Xiaokang Zhang | Jan 21, 2017 | Algorithm & Data Structure
Regular Expression Matching Problem Implement regular expression matching with support for ‘.’ and ‘*’. ‘.’ Matches any single character. ‘*’ Matches zero or more of the preceding element. The matching should cover the...
by Xiaokang Zhang | Jan 20, 2017 | Algorithm & Data Structure
Dynamic programming can be very challenging in that: It is hard to find out whether the question can be solved by dynamic programming or not.It is hard to figure out the correct reduction transition function.It is hard to implement the algorithm correctly. Let’s...