---
id: best-practice-questions
title: Best Practice Questions
---

Here is a suggested schedule for revising and practicing algorithm questions on [LeetCode](https://leetcode.com). Sign up for an account if you don't already have one, it's critical to your success in interviewing!)

## Week 1

In week 1, we will start off easy and do a mix of easy and medium questions on arrays and strings. Arrays and strings are the most common types of questions to be found in interviews; gaining familiarity with them will help in building strong fundamentals to better handle tougher questions.

- [Two Sum](https://leetcode.com/problems/two-sum/)
- [Contains Duplicate](https://leetcode.com/problems/contains-duplicate/)
- [Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/)
- [Valid Anagram](https://leetcode.com/problems/valid-anagram/)
- [Valid Parentheses](https://leetcode.com/problems/valid-parentheses/)
- [Product of Array Except Self](https://leetcode.com/problems/product-of-array-except-self/)
- [Maximum Subarray](https://leetcode.com/problems/maximum-subarray/)
- [3Sum](https://leetcode.com/problems/3sum/)
- [Merge Intervals](https://leetcode.com/problems/merge-intervals/)
- [Group Anagrams](https://leetcode.com/problems/group-anagrams/)

#### Optional

- [Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray/)
- [Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/)

## Week 2

The focus of week 2 is on Linked List, string and matrix-based questions.

- [Reverse a Linked List](https://leetcode.com/problems/reverse-linked-list/)
- [Detect Cycle in a Linked List](https://leetcode.com/problems/linked-list-cycle/)
- [Container With Most Water](https://leetcode.com/problems/container-with-most-water/)
- [Find Minimum in Rotated Sorted Array](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/)
- [Longest Repeating Character Replacement](https://leetcode.com/problems/longest-repeating-character-replacement/)
- [Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/)
- [Number of Islands](https://leetcode.com/problems/number-of-islands/)
- [Remove Nth Node From End Of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list/)
- [Pacific Atlantic Water Flow](https://leetcode.com/problems/pacific-atlantic-water-flow/)
- [Merge K Sorted Lists](https://leetcode.com/problems/merge-k-sorted-lists/)

## Week 3

The focus of week 3 is on non-linear data structures like trees, graphs and heaps.

- [Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree/)
- [Invert/Flip Binary Tree](https://leetcode.com/problems/invert-binary-tree/)
- [Palindromic Substrings](https://leetcode.com/problems/palindromic-substrings/)
- [Non-overlapping Intervals](https://leetcode.com/problems/non-overlapping-intervals/)
- [Serialize and Deserialize Binary Tree](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/)
- [Minimum Window Substring](https://leetcode.com/problems/minimum-window-substring/)
- [Construct Binary Tree from Preorder and Inorder Traversal](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/)
- [Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements/)
- [Clone Graph](https://leetcode.com/problems/clone-graph/)
- [Course Schedule](https://leetcode.com/problems/course-schedule/)
- [Binary Tree Maximum Path Sum](https://leetcode.com/problems/binary-tree-maximum-path-sum/)

#### Optional

- [Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/)
- [Same Tree](https://leetcode.com/problems/same-tree/)
- [Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/)
- [Encode and Decode Strings (Leetcode Premium)](https://leetcode.com/problems/encode-and-decode-strings/)

## Week 4

Week 4 builds up on knowledge from previous weeks but questions are of increased difficulty. Expect to see such level of questions during interviews.

- [Add and Search Word](https://leetcode.com/problems/add-and-search-word-data-structure-design/)
- [Implement Trie (Prefix Tree)](https://leetcode.com/problems/implement-trie-prefix-tree/)
- [Subtree of Another Tree](https://leetcode.com/problems/subtree-of-another-tree/)
- [Kth Smallest Element in a BST](https://leetcode.com/problems/kth-smallest-element-in-a-bst/)
- [Lowest Common Ancestor of BST](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/)
- [Merge K Sorted Lists](https://leetcode.com/problems/merge-k-sorted-lists/)
- [Find Median from Data Stream](https://leetcode.com/problems/find-median-from-data-stream/)
- [Insert Interval](https://leetcode.com/problems/insert-interval/)
- [Longest Consecutive Sequence](https://leetcode.com/problems/longest-consecutive-sequence/)
- [Word Search II](https://leetcode.com/problems/word-search-ii/)

#### Optional

- [Meeting Rooms (Leetcode Premium)](https://leetcode.com/problems/meeting-rooms/)
- [Meeting Rooms II (Leetcode Premium)](https://leetcode.com/problems/meeting-rooms-ii/)
- [Alien Dictionary (Leetcode Premium)](https://leetcode.com/problems/alien-dictionary/)
- [Graph Valid Tree (Leetcode Premium)](https://leetcode.com/problems/graph-valid-tree/)
- [Number of Connected Components in an Undirected Graph (Leetcode Premium)](https://leetcode.com/problems/number-of-connected-components-in-an-undirected-graph/)

## Week 5

Week 5 focuses on Dynamic Programming questions.

- [Climbing Stairs](https://leetcode.com/problems/climbing-stairs/)
- [Coin Change](https://leetcode.com/problems/coin-change/)
- [Longest Increasing Subsequence](https://leetcode.com/problems/longest-increasing-subsequence/)
- [Word Break Problem](https://leetcode.com/problems/word-break/)
- [Combination Sum](https://leetcode.com/problems/combination-sum-iv/)
- [House Robber](https://leetcode.com/problems/house-robber/)
- [House Robber II](https://leetcode.com/problems/house-robber-ii/)
- [Decode Ways](https://leetcode.com/problems/decode-ways/)
- [Unique Paths](https://leetcode.com/problems/unique-paths/)
- [Jump Game](https://leetcode.com/problems/jump-game/)