Python: Solved Interview Ques on Algorithms, Data Structures

Welcome to the course "Python: Solved Interview Questions on Algorithms and Data structures".  

This course is from a software engineer who has managed to crack interviews in around 16 software companies.

Sometimes, life gives us no time to prepare, There are emergency times where in we have to buck up our guts and start  bringing the situations under our control rather then being in the control of the situation.  At the end of the day, All leave this earth empty handed. But given a situation, we should live up or fight up in such a way that the whole action sequence should make us proud and be giving us goosebumps when we think about it right after 10 years.

We would have observed the fact that though most of us are developers, only few would get a chance to work on certain advanced programming stuff like Data Structures, Linked Lists, Trees. The rest of us get to spend time in Bug fixing, resolving Maintenance issues during our work hours. Though this work doesn't help us much in improving our learning curve, it certainly feeds us and our families. So, Keeping this in mind, at the work place, We don't have any option but to work honestly.

But, the real trouble starts when we start attending interviews and suddenly somebody asks us to provide an optimal algorithm or a program which separates zeroes and ones in a array or somebody asks us to provide an efficient algorithm which will get the diameter of a tree. There can also occur a situation where in we think twice or get confused when we try to connect previous and next nodes while inserting a node between two nodes in a single or double link list. 

Most of the times, the interviewer feels happy if we give him/her an optimal solution for a problem. It might so happen that, though we have around 8 to 10 years of software development experience, we still feel shaky and confused while literally tracing or debugging a recursive algorithm. The problem is though we know the solution, We will not be able to present it conveniently as we would have lost touch with the fundamentals of programming due to our day to day office routine, the work processes which are in place.

Speaking of this course, here we have tried to cover majority of interview questions on algorithms and data structures in python along with the basics of data structures. We have literally traced/debugged most of the algorithms for several interview questions. We have explained the solutions for several interview questions for the following content:

Stacks, Linked Lists, Trees, Arrays, Searching and Sorting.

The course content is around 9 hours. Kindly check the preview for 30 mins. If you are interested, Kindly take up the course. The respective programs are attached with the sessions.  Kindly note that, We have focused more on explaining the optimal logic of the program rather then discussing the notations like Big O of the algorithms.

Kindly adjust the talking speed in accordance to your convenience (Please set the course narration speed on your convenience.). The concepts are presented in Neutral English.  

The below are the interview questions explained in the course:

- write a program to implement stacks using lists
- write a program to implement stacks using linked lists
- write a program to balance symbols using stacks
- write a program to convert an infix expression to postfix expression
- write a program to evaluate a postfix expression
- write a program to find out whether a string is a palindrome using stacks
- write a program to reverse a given stack
- write a program to insert a node at the beginning of a single link list
- write a program to insert a node at the end of a single link list
- write a program to insert a node after a particular position in a single link list
- write a program to delete a node at the beginning of a single link list
- write a program to delete a node at the end of the single link list
- write a program to delete a node after a particular position in a single link list
- write a program to search a node in a single link list
- write a program to get the size of a single link list
- write a program to insert a node at the beginning of a double link list
- write a program to insert a node at the end of a double link list
- write a program to insert a node after a particular position in a double link list
- write a program to delete a node at the beginning of a double link list
- write a program to delete a node at the end of the double link list
- write a program to delete a node after a particular position in a double link list
- write a program to find the nth node from the end of the single link list
- write a program which suggests an alternative way to find the nth node from the end of the single link list
- write a program which detects a loop in a single link list
- write a program which finds the length of the loop in a single link list
- write a program which finds the start node of a loop in a single link list
- write a program which reverses the single link list using iteration
- write a program which reverses the single link list using recursion
- write a program which get's us the intersection point of two independent single link lists which are fused at one point
- write a program which finds the middle node of a single link list
- write a program which display the single link list contents beginning from the tail of the list
- write a program which checks if the single link list is even or odd in length
- write a program which merges two independent single linked lists in sorted order
- write a program which reverses the nodes in pairs in a single link list
- write a program which finds the modular node from the end of the single link list
- write a program which finds the modular node from the beginning of the single link list
- write a program which gets the fractional node in a single link list
- write a program which removes the duplicate nodes from a single link list
- write a program which gets the square root node in a single link list
- write a program to add nodes in a binary tree
- write program to find a node in a binary tree
- write a program which displays the contents of a binary tree in an inorder format
- write a program which displays the contents of a binary tree in an preorder format
- write a program which displays the contents of a binary tree in an postorder format
- write a program which checks whether a given tree is a binary tree
- write a program which performs level order traversal on a given binary tree
- write a program which finds the node which has got the maximum value in a given binary tree
- write a program which finds the node which has got the manimum value in a given binary tree
- write a program which finds the node which has got the maximum value using level order traversal in a given binary tree
- write a program which finds the node which has got the minimum value using level order traversal in a given binary tree
- write a program which find the node with a given value using iteration
- write a program which finds the size of the given binary tree using iteration
- write a program which prints the contents of the tree in reverse order using iteration
- write a program which gets the maximum depth of the tree
- write a program which find the deepest node of the tree using iteration
- write a program which counts the number of leaves in the tree using iteration
- write a program which counts the number of full nodes in a tree using iteration
- write a program which counts the number of half nodes in a tree using iteration
- write a program which compares two binary trees
- write a program which find the diameter of a given binary tree
- write a program which gets the level with the maximum sum in a given binary tree
- write a program which gets the path of all nodes in a binary tree
- write a program which gets the combined numbers from root to leaf in a binary tree
- write a program which gets the path which has a given sum in a given binary tree
- write a program which gets the sum of all nodes in a binary tree
- write a program which creates the mirror image of the given binary tree
- write a program which check if two binary trees are mirror images of each other
- write a program which gets the parent of the nodes in a binary tree
- write a program to find duplicated elements in a sorted array
- write a program to find the element which appears maximum number of times in an array
- write a program which gets the non repeated character in the array
- write a program which displays the duplicated numbers in the array
- write a program which gets the repeated character in the array
- write a program which gets the element which has appeared maximum number of times in a array using hashing
- write a program which gets the first repeated element in the array using hashing
- write a program which finds the missing number in a array
- write a program which gets two elements which are present twice in an array using hashing
- write a program which from an array gets the two numbers which form a sum 
- write a program which from an array gets the two numbers when combined is close to zero
- write a program which from an array gets the three numbers which form a sum  
- write a program which from a rotated array, gets the element which has got a minimum value
- write a program which from a rotated array, finds the element with a given value
- write a program which gets the first occurence of a number using binary search in an array
- write a program which gets the last occurence of a number using binary search in an array
- write a program which gets the oddly repeated number in a array
- write a program which seperate even and odd numbers in a array
- write a program which seperate zeroes and ones in the array
- write a programs which seperate zeroes, ones and twos in the array using dutchflag algorithm
- write a program to perform binary search using iteration
- write a program to perform binary search using recursion
- write a program to get the frequency of every number in a array
- write a program which will get the character which has occured only once in the array
- write a program to get the element forming sum from 2 sorted arrays
- write a program to implement bubble sort algorithm
- write a program to implement selection sort algorithm
- write a program to implement shell sort algorithm
- write a program to implement insertion sort algorithm