DSA for Interviews#

This sheet is a collection of important Data Structures and Algorithms (DSA) questions that are frequently asked in technical interviews. It includes a variety of problems, ranging from easy to medium difficulty, primarily focusing on arrays.

🧩 Questions#

#	Question	Difficulty	Topic	Link
1	🔍 Find the duplicate in an array of N integers	🟢 Low	Arrays	View Problem
2	🔄 Sort an array of 0’s 1’s 2’s without using extra space or sorting algo	🟠 Medium	Arrays	View Problem
3	🧮 Repeat and Missing Number	🟢 Low	Arrays	View Problem
4	🧩 Merge two sorted Arrays without extra space	🟠 Medium	Arrays	View Problem
5	⚡ Kadane’s Algorithm	🟠 Medium	Arrays	View Problem
6	📆 Overlapping Subintervals	🟠 Medium	Arrays	View Problem
7	🧊 Set Matrix Zeroes	🟠 Medium	Arrays	View Problem
8	🔺 Pascal Triangle	🟠 Medium	Arrays	View Problem
9	🔁 Next Permutation	🟠 Medium	Arrays	View Problem
10	🔃 Inversion of Array (Using Merge Sort)	🟠 Medium	Arrays	View Problem
11	💹 Stock Buy and Sell	🟠 Medium	Arrays	View Problem
12	🔄 Rotate Matrix	🟢 Low	Arrays	View Problem
13	🔢 Excel Column Number	🟠 Medium	Math	View Problem
14	🧮 Find (n^x) in log N	🟢 Low	Math	View Problem
15	🧮 Trailing Zeroes in Factorial	🟢 Low	Math	View Problem
16	🔗 GCD of Two Numbers	🟢 Low	Math	View Problem
17	🗺️ Grid Unique Paths	🟠 Medium	Math	View Problem
18	🧠 20 Puzzles asked in Interviews	❔ Unknown	Puzzles	View Resource
19	🧮 Two Sum	🟢 Low	Hashing	View Problem
20	🔢 4 Sum	🟠 Medium	Hashing	View Problem