# Ds & Algo Interview Questions for android developers Part 6 of. N

I Have taken most of the questions from people’s **interview reviews** from **glassdoor** and combining them in one place.

**Basic programs:**

- WAP (Write a program) for the alphabet test?
- WAP for Armstrong number?
- Character count in the string?
- WAP to find Factorial of a given number?
- WAP to find fibonacci series?
- WAP to check is given number palindrome?
- WAP to find prime numbers in a given range?
- WAP to print even odd numbers using 2 threads?

**Array Programs:**

- WAP (Write a program) to find duplicate elements in an array?
- WAP to find the 2nd largest number in an array(largest & smallest in an unsorted array, kth smallest or kth largest)?
- WAP to check equality of 2 arrays?
- WAP to find the pair of elements whose sum is equal to the given number?
- WAP to find continuous sub array whose sum is given number?
- WAP to find the intersection of 2 arrays?
- Separate the 0s and 1s in the array?
- Find the missing number in an array?
- WAP to find the occurrence of each element in an array?
- Reverse an array?
- Remove duplicate elements from an array?
- Find common elements in 3 sorted arrays?
- Find 1st repeating element in an array?
- Find 1st non-repeating element in an array?
- Rearrange the number alternate on positive and negative?
- Merge 2 sorted arrays?
- Subarray with maximum sum?
- Maximus stock profit array problem?
- Maximum plateform problem?
- Find the next greater number in an array?
- Replace the element with the next greater number in the array?
- ReversalArrayRotation problem?
- Find the maximum product of a subarray?
- Find the leaders in array?

**String Programs:**

- Check strings are anagram or not?
- Reverse a string?
- Reverse a string sentence?
- Is given string Palindrome?
- Find the longest length character and count (I am a developer (ch=developer, length -9))
- Count all the characters in a string and occurrence of each? (Distinct element)
- Remove duplicate from a string?
- String pattern matcher?
- Find the Longest Common prefix in string array?

**Sorting & Searching Programs:**

- Selection sort.
- Quick sort.
- Bubble sort
- Insertion sort.
- Merge sort.
- Binary Search algorithm
- Search element in a sorted and rotated array?
- Find the index of minimum element in a sorted rotated array?

**Design Patterns Programs:**

- Create a Singleton class?
- WAP for builder design pattern?
- WAP for composite design pattern?
- WAP for facade design pattern?
- WAP for factory and abstract factory design pattern?

**Linked List Doubly Linked List & Circular Linked List Programs:**

- Create a linked list?
- Print the linked list?
- Find the length of the linked list?
- Insert an element at the beginning?
- Insert an element at last?
- Add a new node after a given node?
- Insert the node at a given position?
- Delete the head node?
- Delete the last node?
- Reverse a linked list?
- Detect the loop in the linked list?
- Find the node from where the linked list is looped?
- Remove the loop in the linked list?
- Find the middle element of the linked list?
- Find the nth element from the last linked list?
- Remove duplicate elements in the linked list?
- The intersection point of 2 linked lists?
- Print linked list from the last?
- Segriate even-odd list?

**Queue Programs:**

- Create a queue?
- In queue the element?
- De queue the element?
- Print the queue?
- Queue using 2 stacks?

**Stack Programs:**

- Create a stack?
- Push pop peek operations?
- Get element in O(1)?
- Print the stack?

**Tree Programs:**

- Create a binary Tree?
- PreOrder,InOrder PostOrder travesal?
- Height of binary tree?
- Level order & Vertical order traversal?
- DFS & BFS?
- The mirror image of the tree?
- Min and Max Depth?
- Left, Right & Top, Bottom view of a binary tree?

These are some programs that can help you in your upcoming interviews