Programming interview questions, tips and knowledge, system design, big data.

该节主要讲解sort,uniq,join 命令。 这里对linux常用的命令进行整理，以便日后查看。–来自实验楼。

该节主要讲解wc,grep,正则表达式 命令。 这里对linux常用的命令进行整理，以便日后查看。–来自实验楼。

该节主要讲解df,du,time 命令。 这里对linux常用的命令进行整理，以便日后查看。–来自实验楼。

##题目 ####Longest Consecutive Sequence Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For example,Given [100, 4, 200, 1, 3, 2],The longest consecutive elements sequence is [1, 2, 3, 4]. Return its length: 4. Your algorithm should run in O(n) comple

该节主要讲解which,whereis,locate 命令。 这里对linux常用的命令进行整理，以便日后查看。–来自实验楼。

##题目 ####Longest Valid Parentheses Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring. For "(()", the longest valid parentheses substring is "()", which has length = 2. Another exam

##题目 ####Majority Element Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times. You may assume that the array is non-empty and the majority element always exist in the array. ####Credits:Special thanks to @ts for adding this p

##一、实验内容首先，如果需要打印日志，不需要用log4j这些东西，直接用System.out.println即可，这些输出到stdout的日志信息可以在jobtracker站点最终找到。 其次，如果在main函数启动的时候用System.out.println打印的日志，直接在控制台就可以看到。 再其次，jobtracker站点很重要。 http://localhost:50030 注意，在这里看到Map 100%不一定正确，有时候会卡在Map阶段并没有完成，而此时居然显示Map 100%，所以要一层层的点进去，直到看到日志为止。 另外，在cluster summary表格中可以看到map/

##一、MapReduce介绍MapReduce是一种编程模型，用于大规模数据集（大于1TB）的并行运算。概念"Map（映射）"和"Reduce（归约）"，和他们的主要思想，都是从函数式编程语言里借来的，还有从矢量编程语言里借来的特性。他极大地方便了编程人员在不会分布式并行编程的情况下，将自己的程序运行在分布式系统上。 当前的软件实现是指定一个Map（映射）函数，用来把一组键值对映射成一组新的键值对，指定并发的Reduce（归约）函数，用来保证所有映射的键值对中的每一个共享相同的键组。

##题目 ####Max Points on a Line Given n points on a 2D plane, find the maximum number of points that lie on the same straight line.

##题目 ####Maximal Rectangle Given a 2D binary matrix filled with 0’s and 1’s, find the largest rectangle containing all ones and return its area.

##题目 ####Maximum Depth of Binary Tree Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

##一、实验内容本节介绍Map和Reduce阶段内部细节和调节参数.

##题目 ####Maximum Gap Given an unsorted array, find the maximum difference between the successive elements in its sorted form. Try to solve it in linear time/space. Return 0 if the array contains less than 2 elements. You may assume all elements in the array are non-negative integers and fit in the

##题目 ####Maximum Product Subarray Find the contiguous subarray within an array (containing at least one number) which has the largest product. For example, given the array [2,3,-2,4],the contiguous subarray [2,3] has the largest product = 6.

##题目 ####Maximum Subarray Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [−2,1,−3,4,−1,2,1,−5,4],the contiguous subarray [4,−1,2,1] has the largest sum = 6. ####More practice:If you have figured out the O(n) solu

##题目 ####Merge Intervals Given a collection of intervals, merge all overlapping intervals. For example,Given [1,3],[2,6],[8,10],[15,18],return [1,6],[8,10],[15,18].

##题目 ####Merge Sorted Array Given two sorted integer arrays A and B, merge B into A as one sorted array. Note:You may assume that A has enough space (size that is greater or equal to m + n) to hold additional elements from B. The number of elements initialized in A and B are m and n respectively.

##题目 ####Merge Two Sorted Lists Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.

##题目 ####Merge k Sorted Lists Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.