Tech-Notes

My Striver’s List

Math logic

# Problem Status Level LeetCode Link Answer
1 Swap two numbers without temp ❌ Easy N/A Solution
2 Swap two numbers without arithmetic operations ❌ Medium N/A Solution
3 Count digits ❌ Easy N/A Solution
4 Factorial ❌ Easy N/A Solution
5 Print pattern ❌ Easy N/A Solution
6 Reverse a number ❌ Easy LeetCode Solution
7 Prime ❌ Medium LeetCode Solution
8 Palindrome ❌ Easy LeetCode Solution
9 Armstrong ❌ Medium LeetCode Solution
10 LCM ❌ Easy N/A Solution
11 GCD/HCF ❌ Easy N/A Solution

Searching

# Problem Status Level LeetCode Link Answer
1 Binary Search ❌ Easy LeetCode Solution
1.i Search Insert Position ❌ Easy LeetCode Solution

Sorting

# Problem Status Level LeetCode Link Answer
1 Bubble Sort ❌ Easy N/A Solution
2 Selection Sort ❌ Easy N/A Solution
3 Insertion Sort ❌ Easy N/A Solution
4 Merge Sort ❌ Medium N/A Solution
5 Quick Sort ❌ Medium N/A Solution

Array

# Problem Status Level LeetCode Link Answer
1 Find Second Largest Element ❌ Easy N/A  

String

# Problem Status Level LeetCode Link Answer
1 Reverse a string ❌ Easy LeetCode  
2 Check vowel present in the string ❌ Easy N/A  
3 Remove duplicates in array ❌ Easy N/A  
4 Check string has all unique characters ❌ Easy N/A  
5 Find if one string is permutation of other ❌ Easy N/A  
6 Replace all spaces in a string with ‘%20’ ❌ Easy N/A  
# Problem Status Level LeetCode Link Answer
1 Kadane’s Algorithm ❌ Medium N/A  
2 Dutch National Flag Algorithm ❌ Medium N/A  
3 Sliding Window ❌ Medium N/A  
4 Two Pointers ❌ Medium N/A  

Multidimensional array matrix

# Problem Status Level LeetCode Link Answer
1 Traversal Based Algorithms ❌ Medium N/A  
2 Rotational Based Algorithms ❌ Medium N/A  

Recursion & Backtracking

# Problem Status Level LeetCode Link Answer
1 Basic Recursion Problems ❌ Medium N/A  
2 Divide and Conquer ❌ Medium N/A  
# Problem Status Level LeetCode Link Answer
1 Binary Search on Array ❌ Easy LeetCode  
2 Binary Search on Matrix ❌ Medium N/A  

Data Structure

Linked List

# Problem Status Level LeetCode Link Answer
1 Reverse a Linked List ❌ Easy LeetCode  
2 Sort a Linked List ❌ Medium LeetCode  
3 Detect Cycle in Linked List ❌ Medium LeetCode  
4 Remove N-th Node from End of Linked List ❌ Medium LeetCode  

Stack & Queue

# Problem Status Level LeetCode Link Answer
1 Implement Stack using Array ❌ Easy N/A  
2 Implement Queue using Array ❌ Easy N/A  
3 Implement Stack using Linked List ❌ Medium N/A  
4 Implement Queue using Linked List ❌ Medium N/A  
5 Valid Parentheses (Stack Application) ❌ Easy LeetCode  
6 Implement Min Stack ❌ Medium LeetCode  
7 Sliding Window Maximum (Queue Application) ❌ Hard LeetCode  

Binary Tree

# Problem Status Level LeetCode Link Answer
1 Inorder Traversal ❌ Easy LeetCode  
2 Preorder Traversal ❌ Easy LeetCode  
3 Postorder Traversal ❌ Easy LeetCode  
4 Level Order Traversal ❌ Easy LeetCode  
5 Build Binary Tree from Preorder & Inorder ❌ Medium LeetCode  
6 Build Binary Tree from Inorder & Postorder ❌ Medium LeetCode  
7 Top View of Binary Tree ❌ Medium LeetCode  
8 Bottom View of Binary Tree ❌ Medium LeetCode  
9 Height of Binary Tree ❌ Easy LeetCode  
10 Diameter of Binary Tree ❌ Medium LeetCode  
11 Check if a Binary Tree is Balanced ❌ Medium LeetCode  

Binary Search Tree (BST)

# Problem Status Level LeetCode Link Answer
1 Construct a Binary Search Tree ❌ Medium LeetCode  
2 Convert a BST to a Greater Tree ❌ Medium LeetCode  
3 Convert Sorted Array to BST ❌ Medium LeetCode  
4 Delete Node in a BST ❌ Medium LeetCode  
5 Search a Node in a BST ❌ Easy LeetCode  
6 Find the Minimum Value Node in a BST ❌ Easy LeetCode  
7 Inorder Successor in BST ❌ Medium LeetCode  
8 Validate Binary Search Tree ❌ Medium LeetCode  
9 Lowest Common Ancestor of a BST ❌ Medium    

Priority Queue & Heap

# Problem Status Level LeetCode Link Answer
1 Implement a Min Heap ❌ Medium LeetCode  
2 Implement a Max Heap ❌ Medium LeetCode  
3 Convert a Binary Tree to a Min-Heap ❌ Medium N/A  
4 Convert a Min-Heap to a Max-Heap ❌ Medium N/A  
5 Kth Largest Element in an Array ❌ Medium LeetCode  
6 Kth Smallest Element in an Array ❌ Medium LeetCode  
7 Merge K Sorted Lists ❌ Hard LeetCode  
8 Top K Frequent Elements ❌ Medium LeetCode  
9 Find Median from Data Stream ❌ Hard LeetCode  
10 Reorganize String (Heap) ❌ Medium LeetCode  

Graph

# Problem Status Level LeetCode Link Answer
1 Breadth-First Search (BFS) ❌ Medium LeetCode  
2 Depth-First Search (DFS) ❌ Medium LeetCode  
3 Minimum Spanning Tree (MST) ❌ Medium LeetCode  
4 Dijkstra’s Shortest Path Algorithm ❌ Medium LeetCode  
5 Bellman-Ford Algorithm ❌ Medium LeetCode  
6 Topological Sort ❌ Medium LeetCode  
7 Floyd-Warshall Algorithm ❌ Hard N/A  
8 Graph Representation using Adjacency Matrix ❌ Medium N/A  
9 Graph Representation using Adjacency List ❌ Medium N/A  
10 Detect Cycle in Directed Graph ❌ Medium LeetCode  

Dynamic Programming

# Problem Status Level LeetCode Link Answer
1 DP with Arrays ❌ Medium LeetCode  
2 DP with Strings ❌ Medium LeetCode  
3 DP with Math ❌ Medium LeetCode  
4 DP with Trees ❌ Medium LeetCode  
5 Breaking and Partitioning based problems ❌ Medium LeetCode  
6 Counting based problems ❌ Medium LeetCode  

Hard Recursion and backtracking

Other topics

  1. Hashmaps
  2. Tries
  3. Bit manipulation
  4. Greedy
  5. Circular queue
  6. Deques - Hot topic
  7. Double and circular linkedlist
  8. String algo like KMP and Z algo