DSA Sheets

I have put all important DSA sheets here so you do not need to move from one place to another to find them. I work in Java and follow Striver closely, so I value his sheet highly. The order reflects my own views and I have noted the best use case for each sheet so you can choose what fits your goal. Everything here supports interview preparation and competitive programming, along with some personal useful points below the links.

1. Striver's A2Z DSA Sheet (Best for Interview Preparation)

Direct Link: https://takeuforward.org/strivers-a2z-dsa-course/strivers-a2z-dsa-course-sheet-2/

2. Love Babbar's 450 DSA Sheet (Quick Revision)

Direct Link: https://drive.google.com/file/d/1FMdN_OCfOI0iAeDlqswCiC2DZzD4nPsb/view

3. NeetCode 150 (Best for LeetCode‑Style Practice)

Direct Link: https://neetcode.io/practice

4. Fraz's DSA Sheet (Good Alternative)

Direct Link: https://docs.google.com/spreadsheets/u/0/d/1-wKcV99KtO91dXdPkwmXGTdtyxAfk1mbPXQg81R9sFE/htmlview

5. Apna College’s 375 DSA Sheet (Balanced for Beginner and Intermediate Learners)

Direct Link: https://docs.google.com/spreadsheets/u/0/d/1hXserPuxVoWMG9Hs7y8wVdRCJTcj3xMBAEYUOXQ5Xag/htmlview

6. DSA Sheet by Arsh (45–60 Days Plan)

Direct Link: https://docs.google.com/spreadsheets/d/1MGVBJ8HkRbCnU6EQASjJKCqQE8BWng4qgL0n3vCVOxE/edit#gid=0

7. AlgoPrep’s 151 Problems Sheet

Direct Link: https://docs.google.com/spreadsheets/d/1kyHfGGaLTzWspcqMUUS5Httmip7t8LJB0P-uPrRLGos/edit#gid=0

Always‑Working Tricks for Competitive Programming and Interviews

If input array is sorted

• Binary search
• Two pointers

If asked for all permutations or subsets

• Backtracking

If given a tree

• DFS
• BFS

If given a graph

• DFS
• BFS

If given a linked list

• Two pointers

If recursion is banned

• Stack

If must solve in-place

• Swap corresponding values
• Store several values inside the same pointer

If asked for maximum or minimum subarray or subset

• Dynamic programming

If asked for top or least K items

• Heap
• QuickSelect

If asked for common strings

• Map
• Trie

Else

• Map or Set for O(1) time and O(n) space
• Sort input for O(n log n) time and O(1) space

Word Patterns to Identify the Required Technique

Terms that often imply greedy

• "Minimum number of operations"
• "Choose the best option at each step"

Terms that often imply dynamic programming

• "Maximum sum"
• "Minimum cost"
• "Number of ways"
• "Subsequence"

Terms that often imply sliding window

• "Longest substring"
• "Subarray with..."

Terms that often imply binary search

• "Kth smallest"
• "Search in sorted"
• "Minimize the maximum"

Terms that often imply graph algorithms

• "Network"
• "Connections"
• "Paths"

Click to View: How to Approach Any DSA Question

1. Read the constraints carefully. Identify if the expected solution is O(n), O(n log n), or O(1).
2. Look for keywords that map to common patterns.
3. Identify if the problem reduces to a known template.
4. Break the problem into smaller parts and validate assumptions with sample tests.
5. Start with a simple brute force approach and refine to an optimal method.
6. Check for edge cases at boundaries.