Blind 75

Blind 75 came from a Meta engineer’s post on Blind and is the ancestor of every sheet since. It is deliberately small, which is both its strength and its limit: 75 problems is achievable in two weeks, and 75 problems is not enough to cover greedy, advanced graphs, or the harder DP shapes.

Use it if you are two weeks out, or you want a confidence pass over material you already know. Treat it as the minimum bar, not the target — clearing Blind 75 does not mean you are ready for a Google onsite.

Note that it predates several problems now considered standard, so a few categories look thin by modern standards. That is a property of the list, not a transcription error.

Track it here

Your progress is shared with every other list on this site — tick a problem off here and it is ticked off on its pattern page and in every other sheet that includes it. That is the point of tracking them in one place.

Blind 75

by yangshun / the original Blind post · original sheet

75 problems

The original list, compiled by a Meta engineer. Smaller and older than NeetCode 150 but still the fastest route to broad pattern coverage — treat it as the minimum bar rather than the target.

75 problems

18 easy50 medium7 hard

AllEasyMediumHard

Unsolved onlyExportImportReset

▾Array · 1515

• ○1Two Sumeasyamazongooglemetamicrosoftapplebloomberg
• ○217Contains Duplicateeasyamazonapplemicrosoft
• ○347Top K Frequent Elementsmediumamazonmetauberbytedance
• ○238Product of Array Except Selfmediumamazonmetamicrosoftapple
• ○128Longest Consecutive Sequencemedium
• ○153Summediumamazonmetamicrosoftapplebloomberg
• ○11Container With Most Watermediumamazonmetabloomberg
• ○121Best Time to Buy and Sell Stockeasyamazonmetamicrosoftbloomberg
• ○39Combination Summedium
• ○57Insert Intervalmedium
• ○56Merge Intervalsmediumgooglemetaamazonuberbloomberg
• ○435Non-overlapping Intervalsmedium
• ○252Meeting Roomspremiumeasy
• ○253Meeting Rooms IIpremiummedium
• ○268Missing Numbereasy

▾String · 99

• ○242Valid Anagrameasyamazonmetabloomberg
• ○49Group Anagramsmediumamazonmetauberbloomberg
• ○271Encode and Decode Stringspremiummedium
• ○125Valid Palindromeeasy
• ○3Longest Substring Without Repeating Charactersmediumamazongooglemetamicrosoftbloomberg
• ○424Longest Repeating Character Replacementmedium
• ○76Minimum Window Substringhardmetaamazongoogleuber
• ○5Longest Palindromic Substringmedium
• ○647Palindromic Substringsmedium

▾Stack · 11

• ○20Valid Parentheseseasyamazongooglemetamicrosoftbloomberg

▾Matrix · 33

• ○48Rotate Imagemedium
• ○54Spiral Matrixmedium
• ○73Set Matrix Zeroesmedium

▾Binary Search · 22

• ○153Find Minimum in Rotated Sorted Arraymedium
• ○33Search in Rotated Sorted Arraymediumamazonmetamicrosoftbloomberg

▾Linked List · 66

• ○206Reverse Linked Listeasyamazonmicrosoftapplebloombergmeta
• ○21Merge Two Sorted Listseasyamazonmicrosoftapplebloomberg
• ○141Linked List Cycleeasyamazonmicrosoftbloomberg
• ○143Reorder Listmediumamazonmetabloomberg
• ○19Remove Nth Node From End of Listmedium
• ○23Merge k Sorted Listshard

▾Binary Tree · 88

• ○226Invert Binary Treemedium
• ○104Maximum Depth of Binary Treeeasy
• ○100Same Treeeasy
• ○572Subtree of Another Treeeasy
• ○102Binary Tree Level Order Traversalmediumamazonmetamicrosoftbytedance
• ○105Construct Binary Tree from Preorder and Inorder Traversalmedium
• ○124Binary Tree Maximum Path Sumhard
• ○297Serialize and Deserialize Binary Treehardmetaamazongooglebloomberg

▾Binary Search Tree · 33

• ○235Lowest Common Ancestor of a Binary Search Treemedium
• ○98Validate Binary Search Treemedium
• ○230Kth Smallest Element in a BSTmedium

▾Trie · 33

• ○208Implement Trie (Prefix Tree)mediumgoogleamazonbloomberg
• ○211Design Add and Search Words Data Structuremedium
• ○212Word Search IIhardgoogleamazonbytedance

▾Heap · 11

• ○295Find Median from Data Streamhardamazongooglemetabloomberg

▾Graph · 88

• ○79Word Searchmedium
• ○200Number of Islandsmediumamazongooglemetamicrosoftbytedance
• ○133Clone Graphmediummetagoogleamazon
• ○417Pacific Atlantic Water Flowmedium
• ○207Course Schedulemediumgoogleamazonmetabytedance
• ○323Number of Connected Components in an Undirected Graphpremiummedium
• ○261Graph Valid Treepremiummedium
• ○269Alien Dictionarypremiumhardgooglemetaamazon

▾Dynamic Programming · 1212

• ○70Climbing Stairseasy
• ○198House Robbermedium
• ○213House Robber IImedium
• ○91Decode Waysmedium
• ○322Coin Changemediumamazongooglemicrosoftbytedance
• ○152Maximum Product Subarraymedium
• ○139Word Breakmediumgoogleamazonmetabytedance
• ○300Longest Increasing Subsequencemediumgooglemicrosoftbytedanceuber
• ○62Unique Pathsmedium
• ○55Jump Gamemedium
• ○377Combination Sum IVmedium
• ○53Maximum Subarraymediumamazonmicrosoftbloombergapple

▾Binary · 44

• ○191Number of 1 Bitseasy
• ○338Counting Bitseasy
• ○190Reverse Bitseasy
• ○371Sum of Two Integersmedium

Before you start this sheet

Do the consensus problems first. They are the problems every sheet author independently agreed on, so they are the highest-value problems available regardless of which sheet you eventually commit to.