If you have an interview in 7 days, stop trying to do everything.

Instead, focus on high-frequency patterns that companies like Amazon, Google, Microsoft repeatedly test.

Here’s a curated list of 50 problems that cover ~90% of interview scenarios 👇

Arrays & Hashing

• Two Sum
• Best Time to Buy and Sell Stock
• Contains Duplicate
• Product of Array Except Self
• Maximum Subarray
• Subarray Sum Equals K
• Longest Consecutive Sequence
• Majority Element
• Move Zeroes
• Merge Intervals

Sliding Window / Two Pointers

• Longest Substring Without Repeating Characters
• Longest Repeating Character Replacement
• Minimum Window Substring
• Max Consecutive Ones III
• Permutation in String
• Container With Most Water
• Trapping Rain Water
• Remove Duplicates from Sorted Array

Strings

• Valid Anagram
• Valid Palindrome
• Longest Palindromic Substring
• String Compression
• Group Anagrams
• Reverse Words in a String

Linked List

• Reverse Linked List
• Detect Cycle in Linked List
• Merge Two Sorted Lists
• Remove Nth Node From End
• Intersection of Two Linked Lists
• Add Two Numbers

Stack & Queue

• Valid Parentheses
• Min Stack
• Daily Temperatures
• Next Greater Element
• Evaluate Reverse Polish Notation

Trees

• Binary Tree Inorder Traversal
• Maximum Depth of Binary Tree
• Diameter of Binary Tree
• Invert Binary Tree
• Path Sum
• Lowest Common Ancestor of BST
• Binary Tree Level Order Traversal

Graphs

• Number of Islands
• Clone Graph
• Course Schedule
• Flood Fill

Heap / Greedy

• Kth Largest Element in an Array
• Top K Frequent Elements
• Meeting Rooms II
• Task Scheduler

How to use this list (important):

Don’t rush — focus on patterns
Practice explaining your approach out loud

Always state time & space complexity
Handle edge cases clearly

If you can do even 30–35 of these confidently, you’re in a strong position.

Consistency > volume.
Clarity > tricks.

Good luck to everyone interviewing this season 🚀