DSA guides

Blind 75

Arrays and Hashing

Theory

• Contains Duplicate - Code
• Valid Anagram - Code
• Two Sum - Code
• Group Anagrams - Code
• Top K frequent Elements - Code
• Encode and Decode Strings - Code
• Product of Array Except Self - Code
• Longest Consecutive Sequence - Code

Two Pointers

Theory

• Valid Palindrome - Code
• Three Sum - Code
• Container with most water - Code

Sliding Window

Theory

• Best Time to Buy And Sell Stock - Code
• Longest Substring Without Repeating Characters - Code
• Longest Repeating Character Replacement - Code
• Minimum Window Substring - Code

Stack

Theory

• Valid Parentheses - Code

Binary Search

Theory

• Find Minimum In Rotated Sorted Array - Code
• Find Target in Rotated Sorted Array - Code

Linked List

Theory

• Reverse Linked List - Code

1. Basics

Time & Space Complexity

1. Time & Space Complexity

Recursion

1. Recursion - Basics
2. Backtracking - Basics
3. Parameterized & Functional
4. Functional Recursion
5. Multiple Recursion

Hashing

1. Hashing

2. Sorting

Sorting I

1. Selection Sort
   • Theory | Code
2. Bubble Sort
   • Theory | Code
3. Insertion Sort
   • Theory | Code

Sorting II

1. Merge Sort
   • Theory | Code
2. Recursive Bubble Sort
3. Recursive Insertion Sort
4. Quick Sort
   • Theory | Code

3. Arrays

Easy

1. Largest Element in an Array
   • Theory | Code
2. Second Largest Element in an Array without sorting
   • Theory | Code
3. Check if the array is sorted
   • Theory | Code
4. Remove duplicates from Sorted array
   • Theory | Code
5. Left Rotate an array by one place
6. Left rotate an array by D places
7. Move Zeros to end
8. Linear Search
9. Find the Union
10. Find missing number in an array
11. Maximum Consecutive Ones
12. Find the number that appears once, and other numbers twice.
13. Longest subarray with given sum K(positives)
14. Longest subarray with sum K (Positives + Negatives)

Medium

1. Two Sum Problem
   • Theory | Code
2. Sort an array of 0's 1's and 2's
3. Majority Element (>n/2 times)
4. Kadane's Algorithm, maximum subarray sum
5. Print subarray with maximum subarray sum (extended version of above problem)
6. Stock Buy and Sell
7. Rearrange the array in alternating positive and negative items
8. Next Permutation
9. Leaders in an Array problem
10. Longest Consecutive Sequence in an Array
11. Set Matrix Zeros
12. Rotate Matrix by 90 degrees
13. Print the matrix in spiral manner
14. Count subarrays with given sum

Hard

4. Binary Search (1D Arrays, 2D Arrays, Search Space)

Binary Search - 1D Arrays

Binary Search - 1D Arrays

Binary Search - 2D Arrays

5. Strings

Easy

Medium

Hard

6. Linked List

1D LinkedList

Doubly Linked List

1D LinkedList - Medium

Doubly LinkedList - Medium

1D LinkedList - Hard

7. Recursion

Get a Strong hold

Subsequence Pattern

Trying out all combos/Hard

8. Bit Manipulation

Bit Manipulation

Interview Problems

Advanced Maths

9. Stack & Queues

10. Sliding Window & Two Pointer

Medium

Hard

11. Heaps

Heaps

Medium

Hard

12. Greedy Algorithm

Easy

Medium

Hard

13. Binary Trees

Traversals

Medium

Hard

14. Binary Search Trees

Binary Search Trees

Problems

15. Graph

Graph

BFS/DFS

Topo Sort

Shortest Path Algorithm

Minimum Spanning Tree & Disjoint Set

Other Algorithm

16. Dynamic Programming

Intro

17. Tries

Theory

Problems