Visa Interview Preparation focuses on strengthening the core DSA concepts commonly required in technical interviews, with problems ranging from fundamental to advanced levels.
- Covers Arrays, Strings, Linked Lists, Trees, Graphs, Dynamic Programming, Greedy, Heaps, Stacks & Queues, and Hashing.
- Includes important coding patterns such as Sliding Window, Two Pointers, Binary Search, BFS/DFS, Recursion, and Dynamic Programming.
Arrays
- Two Sum
- Maximum Subarray
- Product of Array Except Self
- Subarray Sum Equals K
- Search in Rotated Sorted Array
- Rotate Array
- Container With Most Water
- Trapping Rain Water
- Sliding Window Maximum
- Longest Consecutive Sequence
Strings
- Longest Substring Without Repeating Characters
- Longest Palindromic Substring
- Longest Common Prefix
- Group Anagrams
- Valid Anagram
- Reverse Words in a String
- Palindromic Substrings
- String to Integer (atoi)
Linked List
- Reverse Linked List
- Merge Two Sorted Lists
- Linked List Cycle
- Intersection of Two Linked Lists
- Reverse Nodes in k-Group
- Merge K Sorted Lists
- Find the Middle of a Linked List
- Add Two Numbers
- Remove Nth Node From End of List
- Clone Linked List with Random Pointer
Stack & Queue
- Valid Parentheses
- Daily Temperatures
- Next Greater Element II
- Largest Rectangle in Histogram
- Sliding Window Maximum
- Implement Queue Using Stacks
- Implement Stack Using Queues
- Simplify Path
- Longest Valid Parentheses
- LRU Cache
Trees & BST
- Binary Tree Level Order Traversal
- Diameter of Binary Tree
- Balanced Binary Tree
- Binary Tree Right Side View
- Lowest Common Ancestor of a Binary Tree
- Sum Root to Leaf Numbers
- Check if Subtree
- Validate Binary Search Tree
- Kth Smallest Element in a BST
- Serialize and Deserialize a Binary Tree
Graphs
- Number of Islands
- Course Schedule
- Rotting Oranges
- Flood Fill
- Clone Graph
- Detect Cycle in a Directed Graph
- Detect Cycle in an Undirected Graph
- Course Schedule II
- Path With Minimum Effort
Dynamic Programming
- Best Time to Buy and Sell Stock
- Best Time to Buy and Sell Stock II
- Maximum Subarray
- House Robber II
- Longest Increasing Subsequence
- Decode Ways
- Word Break
- Partition Equal Subset Sum
- Edit Distance
- Coin Change
Greedy
- Best Time to Buy and Sell Stock II
- Gas Station
- Candy
- Non-overlapping Intervals
- Meeting Rooms
- Maximum Number of Events That Can Be Attended
- Jump Game
- Minimum Suffix Flips
Heap / Priority Queue
- Kth Largest Element in an Array
- Top K Frequent Elements
- Find Median from Data Stream
- Last Stone Weight
- Sliding Window Maximum
- Merge K Sorted Lists
- Top K Frequent Words
- Kth Smallest Element in a Sorted Matrix
Hashing
- Contains Duplicate
- Check If Array Pairs Are Divisible by K
- Check if an Array is a Subset of Another Array
- Array Subset Check
- Count Subarrays with Given XOR
- Smallest Range from K Lists
- Duplicates Within K Distance
- First Non-Repeating Character
- Distinct Elements in Window
- Frequency of Array Elements
- Longest 0-1 Subarray
- Largest Zero-Sum Subarray