Top 10 Algorithms in Interview Questions

Getting ready for a tech job interview? Algorithms are really important! Companies often ask questions that require problem-solving skills. In this article, we'll look at the top 10 algorithms commonly used in interviews. Each algorithm is like a powerful tool in your problem-solving toolbox. Knowing them well can really help you handle different technical challenges during interviews. Let's break down these important algorithms to make your interview preparation more effective. If you're getting ready for a coding interview, it's essential to go through these problems.

1. Array Algorithm

• Maximum Subarray Sum
• Find the Missing Number
• Trapping Rain Water
• Maximum Product Subarray
• Find the equilibrium index of an array
• Leaders in an array
• Minimum Platforms Required for a Railway/Bus Station
• Rotate an array to the right by k steps
• Kth smallest/largest element in an array
• Maximum Length Bitonic Subarray

For more, please refer: Array Data Structure Guide

2. String Algorithm

• Longest Palindromic Substring
• String Matching with Wildcard
• Edit Distance
• Longest Repeating Subsequence
• Count all distinct substrings of a given string
• Reverse words in a given string
• Check if a string is a rotated palindrome
• KMP Algorithm for Pattern Searching
• Minimum characters to be added at front to make string palindrome

For more, please refer: String Data Structure

3. Sorting Algorithm

• QuickSort
• MergeSort
• HeapSort
• Counting Sort
• Radix Sort
• Bubble Sort
• Selection Sort
• Insertion Sort
• Shell Sort
• Bucket Sort

For more, please refer: Sorting Algorithms

4. Searching Algorithm

• Linear Search
• Binary Search
• Ternary Search
• Depth-First Search (DFS)
• Breadth-First Search (BFS)
• Fibonacci Search

For more, please refer: Searching Algorithms

5. Recursion/Backtracking Algorithm

• N-Queens Problem
• Sudoku Solver
• Rat in a Maze
• Word Break Problem using Backtracking
• Subset Sum Problem
• Permutations of a given string
• Combination Sum
• Generate all possible valid IP addresses from given string
• Rat in a Maze with multiple steps or jump allowed

For more, please refer: Recursion/Backtracking Algorithm

6. Greedy Algorithm

• Fractional Knapsack
• Huffman Coding
• Job Sequencing with Deadlines
• Activity Selection Problem
• Greedy Algorithm to find Minimum number of Coins
• Minimum Number of Platforms Required for a Railway/Bus Station
• Maximum Length Chain of Pairs
• Minimize Cash Flow among a given set of friends who have borrowed money from each other
• Connect n Ropes with Minimum Cost
• Prim's Minimum Spanning Tree (MST)

For more, please refer: Greedy Algorithms

7. Tree Algorithm

• Lowest Common Ancestor (LCA)
• Diameter of Binary Tree
• Binary Tree Level Order Traversal
• Serialize and Deserialize a Binary Tree
• Check if a Binary Tree is BST
• Inorder Traversal without Recursion
• Convert Binary Tree to Doubly Linked List
• Check if Two Trees are Identical
• Maximum Width of a Binary Tree
• Mirror of a Binary Tree

For more, please refer: Tree Data Structure

8. Dynamic Programming Algorithm

• Longest Common Subsequence
• 0/1 Knapsack
• Matrix Chain Multiplication
• Longest Increasing Subsequence
• Maximum Sum Increasing Subsequence
• Coin Change Problem
• Longest Palindromic Subsequence
• Edit Distance
• Largest Sum Contiguous Subarray
• Longest Common Substring

For more, please refer: Dynamic Programming

9. Graph Algorithm

• Dijkstra's Algorithm
• Kruskal's Algorithm
• Topological Sorting
• Bellman-Ford Algorithm
• Floyd Warshall Algorithm
• Prim's Algorithm
• Depth-First Traversal of a Graph
• Breadth-First Traversal of a Graph
• Detect Cycle in a Directed Graph
• Articulation Points (or Cut Vertices) in a Graph

For more, please refer: Graph Algorithms

10. Bit Manipulation Algorithm

• Find the Only Non-Repeating Element
• Count Total Set Bits
• Maximum XOR of Two Numbers in an Array
• Find the two non-repeating elements in an array of repeating elements
• Check if a number is sparse or not
• Count total set bits in all numbers from 1 to n
• Maximum subarray XOR in a given array
• Sum of XOR of all subarrays
• Find the element that appears once in an array where every other element appears twice
• Program to find whether a no is power of two

For more, please refer: Bitwise Algorithms

Related Articles:

• Top 50 Array Coding Problems for Interviews
• Top 50 String Coding Problems for Interviews
• Top 50 Problems on Heap Data for Interviews
• Top 50 Tree Coding Problems for Interviews
• Top 50 Dynamic Programming Coding Problems
• Top 50 Graph Coding Problems for Interviews
• Top 50 Problems on Stack Problems for Interviews
• Top 50 Problems on Linked List Problems for Interviews
• Top 50 Problems on Matrix/Grid Problems for Interviews
• Must Do Coding Questions for Product Based Companies
• Must Do Coding Questions for Companies like Amazon