There are a lot of computer science graduates and programmers applying for programming, coding, and software development roles at startups like Uber and Netflix; big organizations like AmazonMicrosoft, and Google; and service-based companies like Infosys or Luxsoft, but many of them have no idea of what kind of programming interview questions to expect when you’re applying for a job with these companies.

已有许多计算机科学专业的毕业生和程序员在 Uber 和 Netflix 等初创公司、亚马逊,微软和谷歌等大型组织,以及诸如 Infosys 或 Luxsoft 这样的服务型公司中申请过编程、编码及软件开发职位,但他们中的许多人都不知道当你在这些公司申请工作时会遇到什么样的编程面试问题

In this article, I’ll share some _frequently asked programming interview questions_from different interviews for programmers at different levels of experience, from people who have just graduated from college to programmers with one to two years of experience.

Coding interviews are comprised mainly of data structure and algorithm-based questions as well as some of the logical questions such as, How do you swap two integers without using a temporary variable?



I think it’s helpful to divide coding interview questions into different topic areas. The topic areas I’ve seen most often in interviews are array, linked list, string, binary tree, as well as questions from algorithms (e.g. string algorithm, sorting algorithms like quicksort or radix sort, and other miscellaneous ones), and that’s what you will find in this article.

我认为将编程面试问题划分到不同的主题区域是很有帮助的。我在面试中经常看到的主题区域是数组、链表、字符串、二叉树,以及源于算法的问题(例如字符串算法,排序算法,如 quicksort 或基数排序,以及其他杂项),这就是你能在这篇文章中找到主要内容。

It’s not guaranteed that you will be asked these coding or data structure and algorithmic questions, but they will give you enough of an idea of the kinds of questions you can expect in a real programming job interview.

Once you have gone through these questions, you should feel confident enough to attend any telephonic or face-to-face interviews.



Btw, there is no point in attempting these questions if you don’t have sufficient knowledge of essential Data Structure and Algorithms or you have not touched them from ages.

In that case, you should take a good course like Algorithms and Data Structures Part 1 and 2 By Robert Horvick to refresh your DS and algorithms skills.


在这种情况下,你应该学习像 Robert Horvick 的算法及数据结构第1部分和第2部分这样的优秀课程以更新你的数据结构和算法技能。

Top 50 Algorithms and Coding Interview Questions

Without any further ado, here is my list of some of the most frequently asked coding interview questions from programming job interviews:

1. Array Coding Interview Questions

An array is the most fundamental data structure, which stores elements at a contiguous memory location. It is also one of the darling topics of interviewers and you will hear a lot of questions about an array in any coding interview, e.g. reversing an array, sorting the array, or searching elements on the array.

The key benefit of an array data structure is that it offers fast O(1) search if you know the index, but adding and removing an element from an array is slow because you cannot change the size of the array once it’s created.

In order to create a shorter or longer array, you need to create a new array and copy all elements from old to new.



1. 数组问题


数组结构的一个关键优点是在知道索引的情况能够以 O(1) 的复杂度找到一个元素。但是增加或者删除一个元素是很慢的,因为一旦创建了一个数组,你就不能改变它的大小了。


The key to solving array-based questions is having a good knowledge of array data structure as well as basic programming constructors such as loop, recursion, and fundamental operators.

Here are some of the popular array-based coding interview questions for your practice:

  1. How do you find the missing number in a given integer array of 1 to 100? (solution)

  2. How do you find the duplicate number on a given integer array? (solution)

  3. How do you find the largest and smallest number in an unsorted integer array? (solution)

  4. How do you find all pairs of an integer array whose sum is equal to a given number? (solution)

  5. How do you find duplicate numbers in an array if it contains multiple duplicates? (solution)

  6. How are duplicates removed from a given array in Java? (solution)

  7. How is an integer array sorted in place using the quicksort algorithm? (solution)

  8. How do you remove duplicates from an array in place? (solution)

  9. How do you reverse an array in place in Java? (solution)

  10. How are duplicates removed from an array without using any library? (solution)

These questions will not only help you to develop your problem-solving skills but also improve your knowledge of array data structure.

If you need more advanced questions based upon array then you can see also seeThe Coding Interview Bootcamp: Algorithms + Data Structures, a bootcamp style course on algorithms, especially designed for interview preparation to get a job on technical giants like Google, Microsoft, Apple, Facebook etc.

And, if you feel 10 is not enough questions and you need more practice, then you can also check out this list of 30 array questions.



  1. 在一个给定的从1到100的整型数组中,如何快速找到缺失的数字?(解决方案

  2. 如何找到一个给定的整型数组中的重复数字?(解决方案

  3. 在一个未排序的整型数组中,如何找到最大和最小的数字?(解决方案

  4. 在一个整型数组中,如何找到一个所有成对的数字,满足它们的和等于一个给定的数字?(解决方案

  5. 如果一个数组包含多个重复元素,如何找到这些重复的数字?(解决方案

  6. 用 Java 实现从一个给定数组中删除重复元素?(解决方案

  7. 如何利用快速排序对一个整型数组进行排序?(解决方案

  8. 如何从一个数组中删除重复元素?(解决方案

  9. 用 Java 实现数组反转?(解决方案

  10. 如何不借助库实现从数组中删除重复元素?(解决方案


如果你需要更多关于数组的进阶的问题,可以参考《代码面试训练营:算法和数据结构》,这是一个训练营形式的算法课程,特别针对像 Google、微软、Apple 和 Facebook 这样的技术巨人面试准备而设计。

如果你感觉 10 个问题还不够,还需要更多的联系,那就看看这个 30 个数组问题的列表。

2. Linked List Programming Interview Questions

linked list is another common data structure that complements the array data structure. Similar to the array, it is also a linear data structure and stores elements in a linear fashion.

However, unlike the array, it doesn’t store them in contiguous locations; instead, they are scattered everywhere in memory, which is connected to each other using nodes.

A linked list is nothing but a list of nodes where each node contains the value stored and the address of the next node.

2. 链表的编程问题




Because of this structure, it’s easy to add and remove elements in a linked list, as you just need to change the link instead of creating the array, but the search is difficult and often requires O(n) time to find an element in the singly linked list.

This article provides more information on the difference between an array and linked list data structures.

It also comes in varieties like a singly linked list, which allows you to traverse in one direction (forward or reverse); a doubly linked list, which allows you to traverse in both directions (forward and backward); and finally, the circular linked list, which forms a circle.

In order to solve linked list-based questions, a good knowledge of recursion is important, because a linked list is a recursive data structure.

基于这种结构,可以很容易实现链表中元素的添加和删除,因为只需要改变节点的指向而无需创建一个新的数组。不过链表中的查找是相对困难的,在一个单向链表中需要花费 O(n) 的时间代价来查找一个元素。




If you take one node from a linked list, the remaining data structure is still a linked list, and because of that, many linked list problems have simpler recursive solutions than iterative ones.

Here are some of the most common and popular linked list interview questions and their solutions:

  1. How do you find the middle element of a singly linked list in one pass? (solution)

  2. How do you check if a given linked list contains a cycle? How do you find the starting node of the cycle? (solution)

  3. How do you reverse a linked list? (solution)

  4. How do you reverse a singly linked list without recursion? (solution)

  5. How are duplicate nodes removed in an unsorted linked list? (solution)

  6. How do you find the length of a singly linked list? (solution)

  7. How do you find the third node from the end in a singly linked list? (solution)

  8. How do you find the sum of two linked lists using Stack? (solution)

These questions will help you to develop your problem-solving skills as well as improve your knowledge of the linked list data structure.

If you are having trouble solving these linked list coding questions then I suggest you refresh your data structure and algorithms skill by going through Data Structures and Algorithms: Deep Dive** Using Java** course.

You can also check out this list of30 linked list interview questions for more practice questions.

如果你从链表中去掉一个节点, 剩下的数据结构仍然是链表,因此, 许多链表问题有比遍历更简单的递归解决方案.


  1. 在一次遍历中,怎样发现单个链表的中间元素? (答案)

  2. 怎样验证给定的链表是环形的? 怎样发现这个环的起始节点? (答案)

  3. 怎样翻转链表? (答案)

  4. 不使用递归,怎样反转单个链表? (答案)

  5. 在未排序链表中,怎样移除重复的节点? (答案)

  6. 怎样找出单个链表的长度? (答案)

  7. 从单个链表的结尾处,怎样找出链表的第三个节点? (答案)

  8. 怎样使用栈计算两个链表的和? (答案)


如果你解决这些链表编码题仍存在问题,我建议你通过 Data Structures and Algorithms: Deep Dive** Using Java** 课程来提升你的数据结构和算法技能.

你也可以从30 linked list interview questions 清单中获取更多练习题.