Table of Contents 

• String_Coding_Question
• Array_Coding_Question
• Stack_Coding_Question
• Queue_Coding_Question
• Linked List_Coding_Question
• Binary_Tree_Coding_Question
• Binary_Search_Coding_Question
• Sorting_Coding_Question
• Graph_Coding_Question
• Dynamic_Programming_Coding_Question
• Miscellaneous_Programming_Coding_Question
• Java8_Coding_Question
• DynamicProgramming_Easy_Question

 

String

• Question 1 : How to reverse a String in java? Can you write a program without using any java inbuilt methods?
• Question 2 : Write a java program to check if two Strings are anagram in java?
• Question 3 : Write a program to check if String has all unique characters in java?
• Question 4 : How to check if one String is rotation of another String in java?
• Question 5 : How to find duplicate characters in String in java?
• Question 6 : Find first non repeated character in String in java?
• Question 7 : Find all substrings of String in java?
• Question 8 : Find length of String without using any inbuilt method in java?
• Question 9 : Write a program to print all permutations of String in java?

 

Array

• Question 10 : Write java Program to Find Smallest and Largest Element in an Array.
• Question 11 : Find missing number in the array.
• Question 12 : Search an element in rotated and sorted array.
• Question 13 : Find minimum element in a sorted and rotated array.
• Question 14: Find second largest number in an array
• Question 15 : Find the number occurring odd number of times in an array
• Question 16 : Find minimum number of platforms required for railway station
• Question 17 : Find a Pair Whose Sum is Closest to zero in Array
• Question 18 : Given a sorted array and a number x, find the pair in array whose sum is closest to x
• Question 19 : Find all pairs of elements from an array whose sum is equal to given number
• Question 20: Given an array of 0’s and 1’s in random order, you need to separate 0’s and 1’s in an array.
• Question 21 : Separate odd and even numbers in an array
• Question 22 : Given an array containing zeroes, ones and twos only. Write a function to sort the given array in O(n) time complexity.
• Question 23 : Find local minima in array
• Question 24 : Sliding window maximum in java
• Question 25 : Count number of occurrences (or frequency) of each element in a sorted array
• Question 26 : Find subarrays with given sum in an array.
• Question 27 : Find peak element in the array.
• Question 28 : Find leaders in an array.
• Question 29 : Count 1’s in sorted Binary Array.
• Question 30 : Find first repeating element in an array of integers.
• Question 31 : Check if Array Elements are Consecutive.
• Question 32 : Permutations of array in java.
• Question 33 : Rotate an array by K positions.
• Question 34 : Stock Buy Sell to Maximize Profit.
• Question 35 : Find maximum difference between two elements such that larger element appears after the smaller number.
• Question 36 : Search in a row wise and column wise sorted matrix.
• Question 37 : Largest sum contiguous subarray.
• Question 38 : Find the Contiguous Subarray with Sum to a Given Value in an array.
• Question 39 : Longest Common Prefix in an array of Strings in java.
• Question 40 : Find all subsets of set (power set) in java.

 

Stack

• Question 41:  Implement a stack using array.
• Question 42: Implement a stack using Linked List.
• Question 43:  Implement a stack using two queues.
• Question 44 : Sort an stack using another stack

 

Queue

• Question 45:  Implement Queue using Array in java.
• Question 46:  Implement a stack using two queues .      

 

Linked List

• Question 47 : Implement singly linked list in java.
• Question 48: How to reverse linked list in java.
• Question 49: How to find middle element of linked list.
• Question 50 : How to find nth element from end of linked list .
• Question 51 : How to detect a loop in linked list. If linked list has loop, find the start node for the loop.
• Question 52: How to check if linked list is palindrome or not?
• Question 53 :  Find intersection of two linked lists?
• Question 54 :  How to reverse a linked list in pairs?
• Question 55 :  Implement Doubly linked list in java?

 

          Binary Tree

• Question 56 : How can you traverse binary tree?
  1. PreOrder
  2. InOrder
  3. PostOrder
• Question 57 : Write an algorithm to do level order traversal of binary tree?
• Question 58 :  Write an algorithm to do spiral order traversal of binary tree?
• Question 59 : How can you print leaf nodes of binary tree?
• Question 60 : How to count leaf nodes of binary tree.
• Question 61 : How to print all paths from root to leaf in binary tree.
• Question 62 : How to find level of node in binary tree
• Question 63 : How to find maximum element in binary tree.
• Question 64 : How to find lowest common ancestor(LCA) in binary tree.
• Question 65 : How to do boundary traversal of binary tree.
• Question 66 : How to print vertical sum of binary tree?
• Question 67 : Count subtrees with Sum equal to target in binary tree?

 

       Binary Search tree

1. Question 68 : What is binary search tree?
2. Question 69 : Can you write algorithm to insert a node in binary search tree.
3. Question 70 : Can you write algorithm to delete a node in binary search tree.
4. Question 71 :  How can you find minimum and maximum elements in binary search tree?
5. Question 72 : How to find lowest common ancestor(LCA) in binary search tree.
6. Question 73 : Find inorder successor in a Binary search Tree
7. Question 74 : Convert sorted array to balanced BST
8. Question 75 : Convert sorted Linked List to balanced BST
9. Question 76 : Check if a binary tree is binary search tree or not in java

 

   Sorting

1. Question 77 : Write an algorithm to implement bubble sort?
2. Question 78 : Write an algorithm to implement insertion sort sort?
3. Question 79 : Write an algorithm to implement selection sort sort?
4. Question 80 : Can you write algorithm for merge sort and also do you know complexity of merge sort?
5. Question 81 : Do you know how to implement Heap sort?
6. Question 82 : Implement quick sort in java?
7. Question 83 : Implement shell sort in java?
8. Question 84 : Implement Counting sort in java?
9. Question 85 : What is binary search? Can you write an algorithm to find an element in sorted array using binary search?

 

Graph

1. Question 86 : Write algorithm to do depth first search in a graph.
2. Question 87 : Write algorithm to do breadth first saearch in a graph.
3. Question 88 : Explain Dijkstra algorithm from source to all other vertices.
4. Question 89 : Explain Bellman Ford algorithm to find shortest distance
5. Question 90 : Explain Kruskal’s algorithm for finding minimum spanning tree

 

Dynamic Programming

1. Question 91 : Given two String, find longest common substring.
2. Question 92 : Given two Strings A and B. Find the length of the Longest Common Subsequence (LCS) of the given Strings.
3. Question 93 : Given a matrix, we need to count all paths from top left to bottom right of MxN matrix. You can either move down or right.
4. Question 94 : Edit Distance Problem in java
5. Question 95: Coin change problem in java
6. Question 96 : Minimum number of jumps to reach last index

 

Miscellaneous

1. Question 97 : What is an algorithm and how to calculate complexity of algorithms.
2. Question 98 : Implement trie data structure in java.
3. Question 99 : Count Factorial Trailing Zeroes in java.
4. Question 100 : Largest Rectangular Area in a Histogram.
5. Question 101 : Check for balanced parentheses in an expression in java.
6. Question 102 : What is Memoization.

 

Java8_Coding

1. Question 1: Given a list of employees, you need to filter all the employee whose age is greater than 20 and print the employee names.(Java 8 APIs only)
2. Question 2: Given the list of employees, count number of employees with age 25?
3. Question 3: Given the list of employees, find the employee with name “Mary”.
4. Question 4: Given a list of employee, find maximum age of employee?
5. Question 5: Given a list of employees, sort all the employee on the basis of age? Use java 8 APIs only
6. Question 6 :Join the all employee names with “,” using java 8?
7. Question 7: Given the list of employee, group them by employee name?
8. Question 8: Java coding interview questions
9. Question 9: Given a list of numbers, square them and filter the numbers which are greater 10000 and then find average of them.( Java 8 APIs only)
10. Question 10: Given a list of integers, find out all the even numbers exist in the list using Stream functions?
11. Question 11: Given a list of integers, find out all the numbers starting with 1 using Stream functions?
12. Question 12 : How to find duplicate elements in a given integers list in java using Stream functions?
13. Question 13: Given the list of integers, find the first element of the list using Stream functions?
14. Question 14: Given a list of integers, find the total number of elements present in the list using Stream functions?
15. Question 15: Given a list of integers, find the maximum value element present in it using Stream functions?
16. Question 16: Given a String, find the first non-repeated character in it using Stream functions?
17. Question 17: Given a String, find the first repeated character in it using Stream functions?
18. Question 18: Given a list of integers, sort all the values present in it using Stream functions?
19. Question 19: Given a list of integers, sort all the values present in it in descending order ausing Stream functions?
20. Question 20 : Flattening nested collections  using java8

 DynamicProgramming_Easy_Question

1. Easy_Question1 : Best Time to Buy and Sell Stock
2. Easy_Question2 : Maximum Subarray
3. Easy_Question3 : Move Zeroes
4. Easy_Question4 : Two Sum
5. Easy_Question5 : Invert Binary Tree
6. Easy_Question6 : Find the Town Judge
7. Easy_Question7 : Symmetric Tree
8. Easy_Question8 : Same Tree
9. Easy_Question9 : House Robber
10. Easy_Question10 : Climbing Stairs
11. Easy_Question11 : Min Cost Climbing Stairs
12. Easy_Question12 : Maximum Depth of Binary Tree
13. Easy_Question13: Find All The Lonely Nodes
14. Easy_Question14 :Check if a binary tree is subtree of another binary tree
15. Easy_Question15 : Lowest Common Ancestor in a Binary Search Tree
16. Easy_Question16 : Shortest Unsorted Continuous Subarray
17. Easy_Question17 :Minimize cost of painting N houses such that adjacent houses have different colors
18. Easy_Question18 : Is Subsequence
19. Easy_Question19 : Merge Two Binary Trees
20. Easy_Question20 : Painting Fence
21. Easy_Question21 :Monotonic Array
22. Easy_Question22 : Leaf-Similar Trees
23. Easy_Question23 : Divisor game
24. Easy_Question24: Convert BST to Greater Tree
25. Easy_Question25 : Majority Element