Case File Library

Start with the origin story.
Book Zero explains why CCF treats every coding problem like an investigation.

Before Correct Code Framework became a system for solving Data Structures and Algorithms, it began with a simple observation: the best investigation games did not teach you to guess.

They taught you to gather clues, eliminate impossible answers, follow constraints, and commit only when the evidence supported the conclusion. That is the same reasoning loop behind correct code.

The Carmen Sandiego Algorithm is the origin story for the Correct Code Framework. It explains how a detective-style investigation becomes a repeatable method for reading problem statements, identifying evidence, eliminating invalid routes, and proving a solution before writing code.

Watch the video to see how that idea became CCF. Then continue into the Case File Library, where the philosophy becomes practice.

They thought they bought a book. They opened a case.

The official Case File Library maps 75 investigations into one progressive reasoning curriculum. Public previews introduce the method, Starter Access opens Case Files #004–#025, and Master DSA or Master Systems Reasoning opens the complete 75-case path.

Case File investigation folder
Public Access

Preview the method

Open Case Files #001–#003 and learn the CCF language before upgrading.

Start Public Preview
Starter Access

Unlock the first path

Continue through Case Files #004–#025 and build the core DSA reasoning foundation.

View Starter Access
Master DSA Access

Complete the curriculum

Your current access: Public Preview. Master DSA opens Case Files #026–#075 and the complete Blind 75 path.

Compare Access Plans

The Official Correct Code Curriculum

Case File Curriculum

26 Hours. 75 Investigations. One Reasoning System.

The Case File path is organized as a guided course, not a loose list of problems. Each hour introduces two or three investigations that build on one another. Every Case File adds a Scanner, Recorder, Frame, Invariant, movement law, proof strategy, or evidence-commitment pattern.

The goal is not to memorize solutions. The goal is to prove why the solution is inevitable.

Public Preview #001–#003 Starter Access #004–#025 Master DSA #026–#075

#004 3 Sum
Starter Access
#005 Sliding Window
Starter Access
#006 Minimum Window
Starter Access

#007 House Robber
Starter Access
#008 Clone Graph
Starter Access
#009 Coin Change
Starter Access

#010 Level Order Traversal
Starter Access
#011 Valid Parentheses
Starter Access
#012 Daily Temperatures
Starter Access

#013 Merge Intervals
Starter Access
#014 Search in Rotated Sorted Array
Starter Access
#015 Kth Largest Element
Starter Access

#016 Top K Frequent Elements
Starter Access
#017 Number of Islands
Starter Access
#018 Course Schedule
Starter Access

#019 Lowest Common Ancestor
Starter Access
#020 Validate Binary Search Tree
Starter Access
#021 Subsets
Starter Access

#022 Combination Sum
Starter Access
#023 Longest Increasing Subsequence
Starter Access
#024 Edit Distance
Starter Access

#025 Word Break
Starter Access
#026 Reverse Linked List
Master DSA
#027 Linked List Cycle
Master DSA

#028 Merge K Sorted Lists
Master DSA
#029 LRU Cache
Master DSA
#030 Trapping Rain Water
Master DSA

#031 Largest Rectangle in Histogram
Master DSA
#032 Find Median from Data Stream
Master DSA
#033 Implement Trie
Master DSA

#034 Word Search II
Master DSA
#035 Accounts Merge
Master DSA
#036 Network Delay Time
Master DSA

#037 Cheapest Flights Within K Stops
Master DSA
#038 Min Cost to Connect All Points
Master DSA
#039 Serialize and Deserialize Binary Tree
Master DSA

#040 Binary Tree Maximum Path Sum
Master DSA
#041 Kth Smallest Element in a BST
Master DSA
#042 Construct Tree from Traversals
Master DSA

#043 N-Queens
Master DSA
#044 Palindrome Partitioning
Master DSA
#045 Decode Ways
Master DSA

#046 Partition Equal Subset Sum
Master DSA
#047 Longest Common Subsequence
Master DSA
#048 Burst Balloons
Master DSA

#049 Regular Expression Matching
Master DSA
#050 Alien Dictionary
Master DSA

#051 Contains Duplicate
Master DSA
#052 Product of Array Except Self
Master DSA
#053 Maximum Subarray
Master DSA

#054 Maximum Product Subarray
Master DSA
#055 Find Minimum in Rotated Sorted Array
Master DSA
#056 Container With Most Water
Master DSA

#057 Sum of Two Integers
Master DSA
#058 Number of 1 Bits
Master DSA
#059 Counting Bits
Master DSA

#060 Missing Number
Master DSA
#061 Reverse Bits
Master DSA
#062 Climbing Stairs
Master DSA

#063 Unique Paths
Master DSA
#064 Jump Game
Master DSA
#065 Longest Repeating Character Replacement
Master DSA

#066 Group Anagrams
Master DSA
#067 Longest Consecutive Sequence
Master DSA
#068 Insert Interval
Master DSA

#069 Non-overlapping Intervals
Master DSA
#070 Meeting Rooms II
Master DSA
#071 Remove Nth Node From End of List
Master DSA

#072 Same Tree
Master DSA
#073 Subtree of Another Tree
Master DSA
#074 Invert Binary Tree
Master DSA

#075 Pacific Atlantic Water Flow
Master DSA