Mapping Computer Science Problems to Real-World Scenarios: A Comprehensive Guide

Here’s a list with a few examples to get started. Please note that the real-world problems and the algorithms aren’t always a one-to-one match. Different real-world problems might use the same algorithm, and the same real-world problem could be solved using different algorithms depending on the specific use-case.

Sequence	Leetcode Number	Problem Name	Real World Problem	Algorithm
1	485	Max Consecutive Ones	Finding longest continuous stretch of a particular event (e.g., days of rain, streak of good sales)	Sliding Window
2	21	Merge Two Sorted Lists	Merging two sorted lists of values (e.g., student grades, sales records)	Merge Sort
3	144	Binary Tree Preorder Traversal	Inventory of goods stored in a hierarchical warehouse	Depth First Search
4	94	Binary Tree Inorder Traversal	Alphabetical listing of employees in a company hierarchy	Depth First Search
5	148	Sort List	Organizing a list of customer orders by order number	Merge Sort
6	977	Squares of a Sorted Array	Ranking cities by the square of their population	Sorting Algorithms
7	283	Move Zeroes	Rearranging a warehouse, placing lesser used items at the back	Two Pointers
8	145	Binary Tree Postorder Traversal	Checking a hierarchical to-do list from bottom to top	Depth First Search
9	707	Design Linked List	Managing the sequence of tasks in a project	Linked List Implementation
10	1089	Duplicate Zeros	Updating a database with zero entries	Two Pointers
11	141	Linked List Cycle	Checking for loops in a workflow	Two Pointers/Floyd’s Cycle Finding Algorithm
12	102	Binary Tree Level Order Traversal	Organizing an agenda according to hierarchical priorities	Breadth First Search

Mapping Table

Sequence	Leetcode Number	Problem Name	Real World Problem	Algorithm
1	485	Max Consecutive Ones	Finding longest continuous quality control passes	Array Traversal
2	21	Merge Two Sorted Lists	Merging two sorted patient lists	Merge Sort
3	144	Binary Tree Preorder Traversal	Prioritizing tasks in a project	Depth-First Search
4	94	Binary Tree Inorder Traversal	Cataloguing books in a library system	Depth-First Search
5	148	Sort List	Sorting a list of employees by ID	Merge Sort
6	977	Squares of a Sorted Array	Sorting cities by squares of population	Sorting
7	283	Move Zeroes	Rearranging boxes in a warehouse	Two Pointers
8	145	Binary Tree Postorder Traversal	Deallocating resources in a dependency order	Depth-First Search
9	707	Design Linked List	Organizing a to-do list	Linked List Design
10	1089	Duplicate Zeros	Expanding coded messages	Array Manipulation
11	141	Linked List Cycle	Detecting circular references in a document	Two Pointers
12	102	Binary Tree Level Order Traversal	Managing multi-level marketing structure	Breadth-First Search
13	104	Maximum Depth of Binary Tree	Determining highest level of a business hierarchy	Depth-First Search
14	142	Linked List Cycle II	Detecting repeat tasks in a project plan	Two Pointers
15	88	Merge Sorted Array	Merging two ordered lists of customers	Two Pointers
16	75	Sort Colors	Sorting clothes by color	Dutch National Flag Problem
17	101	Symmetric Tree	Checking balance in a company’s organization structure	Depth-First Search
18	160	Intersection of Two Linked Lists	Finding common members in two different teams	Two Pointers
19	27	Remove Element	Removing discontinued products from a catalog	Two Pointers
20	19	Remove Nth Node From End of List	Removing a particular item from a task list	Two Pointers
21	112	Path Sum	Calculating costs on a particular route	Depth-First Search
22	250	Count Univalue Subtrees	Counting departments with the same performance rating	Depth-First Search
23	206	Reverse Linked List	Reversing a sequence of events	Linked List Manipulation
24	26	Remove Duplicates from Sorted Array	Removing duplicate records from a sorted list	Two Pointers
25	1346	Check If N and Its Double Exist	Checking if an employee’s salary is double another’s	Hash Table
26	100	Same Tree	Checking if two organization charts are identical	Depth-First Search
27	24	Swap Nodes in Pairs	Reordering tasks in pairs	Linked List Manipulation
28	941	Valid Mountain Array	Checking if sales figures form a peak pattern	Array Traversal
29	589	N-ary Tree Preorder Traversal	Prioritizing tasks in a multi-dependent project	Depth-First Search
30

509 | Fibonacci Number | Predicting rabbit population growth | Dynamic Programming | | 31 | 70 | Climbing Stairs | Counting the ways to climb a staircase | Dynamic Programming | | 32 | 590 | N-ary Tree Postorder Traversal | Completing tasks in a multi-dependent project | Depth-First Search | | 33 | 1299 | Replace Elements with Greatest Element on Right Side | Reordering tasks based on priority | Array Traversal | | 34 | 905 | Sort Array By Parity | Organizing tasks based on type | Two Pointers | | 35 | 50 | Pow(x, n) | Computing an interest rate over time | Binary Search | | 36 | 429 | N-ary Tree Level Order Traversal | Managing a multi-level marketing structure | Breadth-First Search | | 37 | 344 | Reverse String | Reversing a sequence of events | Two Pointers | | 38 | 559 | Maximum Depth of N-ary Tree | Determining highest level of a complex organization | Depth-First Search | | 39 | 22 | Generate Parentheses | Generating valid sequence of operations | Depth-First Search | | 40 | 217 | Contains Duplicate | Checking for duplicate records in a list | Hash Table | | 41 | 431 | Encode N-ary Tree to Binary Tree | Reducing complexity of a project plan | Tree Manipulation | | 42 | 912 | Sort an Array | Sorting a list of items | Quick Sort | | 43 | 33 | Search in Rotated Sorted Array | Searching a cyclically ordered catalog | Binary Search | | 44 | 198 | House Robber | Planning a schedule to maximize profit | Dynamic Programming | | 45 | 700 | Search in a Binary Search Tree | Searching an organized record system | Binary Search | | 46 | 81 | Search in Rotated Sorted Array II | Searching a cyclically ordered catalog with duplicates | Binary Search | | 47 | 98 | Validate Binary Search Tree | Validating an ordered system | Depth-First Search | | 48 | 121 | Best Time to Buy and Sell Stock | Maximizing profit by buying and selling stocks | Dynamic Programming | | 49 | 876 | Middle of the Linked List | Finding the middle item in a list | Two Pointers | | 50 | 270 | Closest Binary Search Tree Value | Finding the closest price in a sorted list | Depth-First Search | | 51 | 153 | Find Minimum in Rotated Sorted Array | Finding the smallest number in a cyclically ordered set | Binary Search | | 52 | 252 | Meeting Rooms | Checking if meeting times overlap | Sorting and Sweep Line | | 53 | 704 | Binary Search | Searching a sorted list of items | Binary Search | | 54 | 83 | Remove Duplicates from Sorted List | Removing duplicate records from a sorted list | Two Pointers | | 55 | 203 | Remove Linked List Elements | Removing specific tasks from a project plan | Two Pointers | | 56 | 852 | Peak Index in a Mountain Array | Finding the peak sales period | Binary Search | | 57 | 637 | Average of Levels in Binary Tree | Averaging performance metrics across an organization | Breadth-First Search | | 58 | 234 | Palindrome Linked List | Checking if a sequence of events is the same forwards and backwards | Two Pointers | | 59 | 111 | Minimum Depth of Binary Tree | Determining the shortest chain of command | Breadth-First Search | | 60 | 162 | Find Peak Element | Finding peak sales period | Binary Search | | 61 | 543 | Diameter of

Note: These are broad examples and the real-world applications of these algorithms may vary based on specific use cases. The same real-world problem could be solved using different algorithms or data structures, and the same algorithm could be used to solve different real-world problems.

Here is the same table for more problems:

Problem Name	Real World Problem	Algorithm
Palindromic Substrings	Checking for reversible words in a document	Dynamic Programming
Number of Longest Increasing Subsequence	Finding longest sequence of progress in life events	Dynamic Programming
Partition Equal Subset Sum	Distributing tasks equally among workers	Dynamic Programming
Number of Islands	Identifying separated land masses on a map	Depth-First Search
Pacific Atlantic Water Flow	Determining water flow in geographical terrains	Depth-First Search
Clone Graph	Copying social network connections	Breadth-First Search/Depth-First Search
Reorder List	Arranging documents in a particular order	Two Pointers
Sort List	Arranging items in an inventory	Merge Sort
Remove Nth Node From End of List	Removing a particular item from a list	Two Pointers
Add Two Numbers	Performing large number arithmetic	Linked List
Best Time to Buy and Sell Stock with Cooldown	Optimizing stock trading with cooldowns	Dynamic Programming
Odd Even Linked List	Organizing a list into odd and even indices	Two Pointers
Swap Nodes in Pairs	Pairing and swapping items in a list	Linked List
Rotate List	Rotating items in a list	Two Pointers
Number of Connected Components in an Undirected Graph	Counting groups in a social network	Depth-First Search/Breadth-First Search
Graph Valid Tree	Checking if a network can be organized as a tree	Depth-First Search
Task Scheduler	Scheduling tasks with cooldowns	Heap/Priority Queue
Non-overlapping Intervals	Scheduling meetings in different rooms	Greedy Algorithm
Interval List Intersections	Finding overlaps in schedules	Two Pointers
Merge Intervals	Merging overlapping time intervals	Sorting
Find K Pairs with Smallest Sums	Finding most compatible pairs in two groups	Heap
Kth Smallest Element in a Sorted Matrix	Finding a rank in a competition	Binary Search
Find K Closest Elements	Finding closest locations to a point	Binary Search
Search a 2D Matrix II	Searching a database	Binary Search
Search a 2D Matrix	Searching a database	Binary Search
Search in Rotated Sorted Array II	Searching for an item in a shifted database	Binary Search
Search in Rotated Sorted Array	Searching for an item in a shifted database	Binary Search
Find Peak Element	Finding a local maximum in a graph	Binary Search
Find Minimum in Rotated Sorted Array	Finding a local minimum in a shifted graph	Binary Search
Minimum Number of Arrows to Burst Balloons	Strategizing in a balloon shooting game	Greedy Algorithm
Minimum Height Trees	Finding the minimum height trees in a forest	Breadth-First Search
Course Schedule II	Scheduling university courses	Depth-First Search
Course Schedule	Checking if a university course schedule is possible	Depth-First Search
Reorganize String	Arranging characters in a way to avoid repetition	Heap
Kth Largest Element in an Array	Finding a rank in a competition	Heap
Sort Characters By Frequency	Counting character frequency in a document	Heap
Top K Frequent Elements	Identifying the most frequent items in a database	Heap
K Closest Points to Origin	Finding the nearest locations to a point	Heap
Kth Smallest Element in a BST	Finding a rank in a competition	Binary Search Tree
Longest Repeating Character Replacement	Modifying a document to create long repeated character strings	Two Pointers
Permutation in String	Checking if a document contains any anagram of a word	Two Pointers
Fruit Into Baskets	Optimizing collection of different types of items	Two Pointers
Minimum Size Subarray Sum	Minimizing a window to meet a certain criteria	Two Pointers
3Sum	Finding triplets in a set that add up to a certain number	Two Pointers
Implement Trie (Prefix Tree)	Autocompleting a search query	Trie
3Sum Closest	Finding triplets closest to a target sum	Two Pointers
Validate Binary Search Tree	Checking if a book index follows a binary search tree property	Depth-First Search
Construct Binary Tree from Preorder and Inorder Traversal	Constructing a family tree given certain properties	Depth-First Search
Maximum Width of Binary Tree	Finding the maximum width of a hierarchy	Depth-First Search
Maximum Binary Tree	Constructing a hierarchy with maximum property	Depth-First Search
Path Sum III	Finding all the paths in a financial tree that sum to a certain amount	Depth-First Search
Path Sum II	Finding all the paths in a project tree that sum to a certain amount	Depth-First Search
All Nodes Distance K in Binary Tree	Finding all nodes at a certain distance in a network	Breadth-First Search
Binary Tree Right Side View	Viewing a hierarchy from a certain angle	Depth-First Search
Populating Next Right Pointers in Each Node II	Linking elements in a hierarchy	Breadth-First Search
Populating Next Right Pointers in Each Node	Linking elements in a hierarchy	Breadth-First Search
Binary Tree Zigzag Level Order Traversal	Traversing a hierarchy in a zigzag pattern	Breadth-First Search
Longest Substring Without Repeating Characters	Finding the longest unique section in a document	Sliding Window
Sliding Window Maximum	Finding the maximum in each window of a list	Deque
Count of Range Sum	Counting the number of sums in a range	Merge Sort
Graph Valid Tree	Checking if a network can be organized as a tree	Depth-First Search
Meeting Rooms II	Scheduling meeting rooms	Heap
Insert Interval	Inserting an interval in a schedule	Sorting
Container With Most Water	Maximizing water storage between points	Two Pointers
Trapping Rain Water	Calculating rainwater trapped between buildings	Two Pointers
Sequence Reconstruction	Checking if a sequence can be reconstructed from subsequences	Topological Sort
Alien Dictionary	Constructing a dictionary from alien words	Topological Sort

Real World Applications

Here’s the table for the problems along with a column for real-world applications:

Problem Name	Real World Problem	Algorithm	Real World Application/Product
N-Queens	Positioning multiple servers to avoid interference	Backtracking	GPS positioning systems
Smallest Range Covering Elements from K Lists	Finding a minimal range in different measurements	Heap	Climate change analysis
Merge k Sorted Lists	Merging multiple sorted datasets	Heap	Database management systems
Reverse Nodes in k-Group	Reversing sections of a list	Linked List	Data manipulation in Excel
Sudoku Solver	Solving a Sudoku game	Backtracking	Sudoku apps
Longest Consecutive Sequence	Finding the longest streak in data	Hashing	Activity trackers like Fitbit
First Missing Positive	Finding missing information in data	Array manipulation	Database management
Maximum XOR of Two Numbers in an Array	Finding the maximum XOR operation result	Trie	Data encryption
Sort Colors	Sorting data by categories	Two Pointers	Inventory management systems
Subarray Product Less Than K	Finding product sections within a limit	Two Pointers	Inventory forecasting
Substring with Concatenation of All Words	Finding all words in a document	Sliding Window	Search engines like Google
Minimum Window Substring	Finding the smallest relevant section in a document	Sliding Window	Text Editors
Count Unique Characters of All Substrings of a Given String	Counting unique substrings	Sliding Window	Data compression software
Minimum Number of K Consecutive Bit Flips	Manipulating bit data	Sliding Window	Network protocol design
Employee Free Time	Finding free time in employee schedules	Heap	HR software like Workday
Smallest Range Covering Elements from K Lists	Finding a minimal range in different measurements	Heap	Climate change analysis
Median of Two Sorted Arrays	Finding the median from multiple datasets	Binary Search	Statistics software
Sort Items by Groups Respecting Dependencies	Sorting tasks considering dependencies	Topological Sort	Project management tools like Asana
Word Squares	Forming words in a grid	Trie, Backtracking	Crossword puzzle generators
Design Search Autocomplete System	Autocompleting a search query	Trie, Heap	Google Search
Palindrome Pairs	Finding palindrome pairs	Trie, Hashing	Data analysis software
Prefix and Suffix Search	Searching for words with certain prefixes and suffixes	Trie	Google Search
Concatenated Words	Finding concatenated words	Dynamic Programming	Natural language processing tools
Sliding Window Median	Finding the median in a sliding window	Sliding Window, Heap	Real-time data analysis tools
Find Median from Data Stream	Finding the median in a data stream	Heap	Real-time data analysis tools
Word Search II	Searching for multiple words in a grid	Trie, Depth-First Search	Word search game apps
Serialize and Deserialize Binary Tree	Storing and retrieving tree structures	Depth-First Search	Database systems
Binary Tree Maximum Path Sum	Finding the maximum path sum in a tree	Depth-First Search	Network routing algorithms
Maximum Frequency Stack	Designing a stack with maximum frequency retrieval	Stack, Heap	Cache design
Course Schedule III	Scheduling tasks with deadlines	Heap	Project management tools like Trello
Rearrange String k Distance Apart	Arranging tasks with minimum gap	Heap, Queue	CPU task scheduling
Substring with Concatenation of All Words	Finding all words in a document	Sliding Window	Search engines like Google
Sliding Window Maximum	Finding the maximum

I can provide potential real-world applications or product scenarios where these problems might be relevant:

First Bad Version (278)
- Problem Category: Binary Search
- Real World Problem: Identifying the point of failure in a sequence of system versions.
- Algorithm: Binary Search
- Application: Software versioning systems in companies like Microsoft, Apple, etc. where it’s crucial to identify the exact version where a bug was introduced.
Pascal’s Triangle II (119)
- Problem Category: Dynamic Programming
- Real World Problem: Calculating the specific row of mathematical structure Pascal’s Triangle.
- Algorithm: Dynamic Programming
- Application: In mathematical software or tools (like Mathematica, MATLAB) where computation of combinatorial mathematics is needed.
Valid Perfect Square (367)
- Problem Category: Binary Search
- Real World Problem: Checking if a given number is a perfect square.
- Algorithm: Binary Search
- Application: In geometry-based software tools or mathematical modeling software where calculations involving squares and roots are frequently required.
Find Smallest Letter Greater Than Target (744)
- Problem Category: Binary Search
- Real World Problem: Searching for the next larger element in a cyclically sorted list.
- Algorithm: Binary Search
- Application: In text-editing or word-processing software (like Microsoft Word, Google Docs), such a feature might be used for providing suggestions or autocompletions.
Find K-th Smallest Pair Distance (719)
- Problem Category: Binary Search, Sliding Window
- Real World Problem: Finding the k-th smallest distance among all possible pair distances in a list.
- Algorithm: Binary Search and Sliding Window
- Application: In geographic information systems (GIS) or navigation applications (like Google Maps), this problem could relate to finding the k-th shortest distance between pairs of locations.
Split Array Largest Sum (410)
- Problem Category: Binary Search, Dynamic Programming
- Real World Problem: Dividing an array into sections to minimize the largest sum of any section.
- Algorithm: Binary Search and Dynamic Programming
- Application: This type of problem might come up in resource allocation in cloud services (like Amazon AWS, Google Cloud) where workloads need to be evenly distributed across different servers to prevent overloading any particular one.