### Data Structure Interview Questions

No. 10 - K-th Node from End
Get the Kth node from end of a linked list. It counts from 1 here, so the 1st node from end is the tail of list.

No. 18 - Reverse a Linked List
Implement a function to reverse a linked list, and return the head of the reversed list.

No. 29 - Loop in List
How to check whether there is a loop in a linked list? If there is a loop in a linked list, how to get the entry node of the loop?

No. 40 - Add on Lists
Nodes in a list represent a number. Please implement a function/method to add numbers in two lists, and store the sum into a new list.

### 2. Binary Tree

No. 01 - Binary Search Tree and Double-linked List
Convert a binary search tree to a sorted double-linked list. We can only change the target of pointers, but cannot create any new nodes.

No. 04 - Paths with Specified Sum in Binary Tree
All nodes along children pointers from root to leaf nodes form a path in a binary tree. Given a binary tree and a number, please print out all of paths where the sum of all nodes value is same as the given number.

No. 06 - Post-order Traversal Sequences of Binary Search Trees
Determine whether an input array is a post-order traversal sequence of a binary tree or not. If it is, return true; otherwise return false. Assume all numbers in an input array are unique.

No. 31 - Binary Search Tree Verification
How to verify whether a binary tree is a binary search tree?

No. 45 - Closest Node in a Binary Search Tree
Given a binary search tree and a value k, please find a node in the binary search tree whose value is closest to k.

Given a binary search tree, please check whether there are two nodes in it whose sum equals a given value.

### 3. String

No. 07 - Reverse words in a sentence
Reverse the order of words in a sentence, but keep words themselves unchanged. Words in a sentence are divided by blanks. For instance, the reversed output should be “student. a am I” when the input is “I am a student”.

No. 13 - First Character Appearing Only Once
Implement a function to find the first character in a string which only appears once.
For example: It returns ‘b’ when the input is “abaccdeff”.

No. 19 - Left Rotation of String
Left rotation of a string is to move some leading characters to its tail. Please implement a function to rotate a string. For example, if the input string is “abcdefg” and a number 2, the rotated result is “cdefgab”.

No. 43 - Minimal Number of Palindromes on a String
A string can be partitioned into some substrings, such that each substring is a palindrome. For example, there are a few strategies to split the string “abbab” into palindrome substrings, such as: “abba”|”b”, “a”|”b”|”bab” and “a”|”bb”|”a”|”b”.

No. 55 - Translating Numbers to Strings
Given a number, please translate it to a string, following the rules: 1 is translated to 'a', 2 to 'b', …, 12 to 'l', …, 26 to 'z'. For example, the number 12258 can be translated to "abbeh", "aveh", "abyh", "lbeh" and "lyh", so there are 5 different ways to translate 12258. How to write a function/method to count the different ways to translate a number?

### 4. Array and Matrix

No. 22 - Turning Number in an Array
Turning number is the maximum number in an array which increases and then decreases. This kind of array is also named unimodal array. Please write a function which gets the index of the turning number in such an array.
For example, the turning number in array {1, 2, 3, 4, 5, 10, 9, 8, 7, 6} is 10, so its index 5 is the expected output.

Please implement a function which gets the intersection of two sorted arrays. Assuming numbers in each array are unique.

No. 34 - String Path in Matrix
How to implement a function to check whether there is a path for a string in a matrix of characters? It moves to left, right, up and down in a matrix, and a cell for a movement. The path can start from any entry in a matrix. If a cell is occupied by a character of a string on the path, it cannot be occupied by another character again.

No. 41 - Group of 1s in a Matrix
Given a matrix with 1s and 0s, please find the number of groups of 1s. A group is defined by horizontally or vertically adjacent 1s.

No. 56 - Maximal Value of Gifts
A board has n*m cells, and there is a gift with some value (value is greater than 0) in every cell. You can get gifts starting from the top-left cell, and move right or down in each step, and finally reach the cell at the bottom-right cell. What’s the maximal value of gifts you can get from the board?

### 5. Stack and Queue

Define a stack, in which we can get its minimum number with a function min. In this stack, the time complexity of min(), push() and pop() are all O(1).

Implement a queue with two stacks. Please implement two functions: appendTail to append an element into tail of a queue, and deleteHead to delete an element from head of a queue.

Given two integer sequences, one of which is the push sequence of a stack, please check whether the other sequence is a corresponding pop sequence or not.

For example, if 1, 2, 3, 4, 5 is a push sequence, 4, 5, 3, 2, 1 is a corresponding pop sequence, but the sequence 4, 3, 5, 1, 2 is not.

Given an array of numbers and a sliding window size, how to get the maximal numbers in all sliding windows?

How can you implement n (n >= 2) stacks in a single array, where no stack overflows until no space left in the entire array space?

1. Books to be referred to prepare for soft skill development?
soft skills training for college students

2. This is an awesome post.Really very informative and creative contents. These concept is a good way to enhance the knowledge.I like it and help me to article very well.Thank you for this brief explanation and very nice information.Well, got a good knowledge.
DedicatedHosting4u.com

3. Thank you for sharing this great post, I am very impressed with your post, the information provided is meticulous and easy to understand. I will regularly follow your next post.

Thanks
Cpa offers

4. Your post is very good. I got to learn a lot from your post. Thank you for sharing your article for us. it is amazing post
what is seo
types of seo

5. This is a fantastic idea! I like it a lot because it's super easy for the audience to see the value of opting in. wonderful and amazing post very use full your post thanks for sharing your article
Android Application development
Web application