HackerRank hosts challenges to learn, practice, and refine your programming skills. This repository contains my solutions to HackerRank challenges.
Please note that this README is dynamically updated. I created scripts in the automation
directory to (1) webscrape challenge information, (2) update this README file, and (3) select challenges to complete and push commits to this repository.
Contains solutions to sql using MySQL.
NOTE: When using Common Table Expressions (CTE), must use the MS SQL Server Console.
Contains solutions to Basic Select.
Number | Challenge | Score | Difficulty | Rate | Solution |
---|---|---|---|---|---|
1 | Revising the Select Query I | 10 | ⭐ | 96.02% | sql |
2 | Revising the Select Query II | 10 | ⭐ | 98.82% | sql |
3 | Select All | 10 | ⭐ | 99.69% | sql |
4 | Select By ID | 10 | ⭐ | 99.71% | sql |
5 | Japanese Cities' Attributes | 10 | ⭐ | 99.69% | sql |
6 | Japanese Cities' Names | 10 | ⭐ | 99.72% | sql |
7 | Weather Observation Station 1 | 15 | ⭐ | 99.53% | sql |
8 | Weather Observation Station 3 | 10 | ⭐ | 97.48% | sql |
9 | Weather Observation Station 4 | 10 | ⭐ | 98.55% | sql |
10 | Weather Observation Station 5 | 30 | ⭐ | 93.24% | sql |
11 | Weather Observation Station 6 | 10 | ⭐ | 98.45% | sql |
12 | Weather Observation Station 7 | 10 | ⭐ | 99.10% | sql |
13 | Weather Observation Station 8 | 15 | ⭐ | 98.62% | sql |
14 | Weather Observation Station 9 | 10 | ⭐ | 99.17% | sql |
15 | Weather Observation Station 10 | 10 | ⭐ | 99.47% | sql |
16 | Weather Observation Station 11 | 15 | ⭐ | 98.51% | sql |
17 | Weather Observation Station 12 | 15 | ⭐ | 98.79% | sql |
18 | Higher Than 75 Marks | 15 | ⭐ | 98.86% | sql |
19 | Employee Names | 10 | ⭐ | 99.74% | sql |
20 | Employee Salaries | 10 | ⭐ | 99.67% | sql |
Contains solutions to Advanced Select.
Number | Challenge | Score | Difficulty | Rate | Solution |
---|---|---|---|---|---|
1 | Type of Triangle | 20 | ⭐ | 95.81% | sql |
2 | The PADS | 30 | ⭐⭐ | 93.19% | sql |
Contains solutions to Aggregation.
Number | Challenge | Score | Difficulty | Rate | Solution |
---|---|---|---|---|---|
1 | Revising Aggregations - The Count Function | 10 | ⭐ | 99.50% | sql |
2 | Revising Aggregations - The Sum Function | 10 | ⭐ | 99.64% | sql |
3 | Revising Aggregations - Averages | 10 | ⭐ | 99.80% | sql |
4 | Average Population | 10 | ⭐ | 99.53% | sql |
5 | Japan Population | 10 | ⭐ | 99.86% | sql |
6 | Population Density Difference | 10 | ⭐ | 99.84% | sql |
7 | The Blunder | 15 | ⭐ | 97.83% | sql |
8 | Top Earners | 20 | ⭐ | 97.90% | sql |
9 | Weather Observation Station 2 | 15 | ⭐ | 99.37% | sql |
10 | Weather Observation Station 13 | 10 | ⭐ | 99.49% | sql |
11 | Weather Observation Station 14 | 10 | ⭐ | 99.69% | sql |
12 | Weather Observation Station 15 | 15 | ⭐ | 98.99% | sql |
13 | Weather Observation Station 16 | 10 | ⭐ | 99.77% | sql |
14 | Weather Observation Station 17 | 15 | ⭐ | 99.34% | sql |
15 | Weather Observation Station 18 | 25 | ⭐⭐ | 98.52% | sql |
16 | Weather Observation Station 19 | 30 | ⭐⭐ | 98.44% | sql |
17 | Weather Observation Station 20 | 40 | ⭐⭐ | 96.28% | sql |
Contains solutions to Basic Join.
Number | Challenge | Score | Difficulty | Rate | Solution |
---|---|---|---|---|---|
1 | Asian Population | 10 | ⭐ | 98.43% | sql |
2 | African Cities | 10 | ⭐ | 99.37% | sql |
3 | Average Population of Each Continent | 10 | ⭐ | 97.94% | sql |
4 | The Report | 20 | ⭐⭐ | 96.98% | sql |
5 | Top Competitors | 30 | ⭐⭐ | 96.11% | sql |
6 | Ollivander's Inventory | 30 | ⭐⭐ | 94.08% | sql |
7 | Challenges | 30 | ⭐⭐ | 92.02% | sql |
8 | Contest Leaderboard | 30 | ⭐⭐ | 97.44% | sql |
Contains solutions to 10 Days of Statistics.
All solutions (excluding multivariate linear regression) are implemented in Python 3 without using 3rd party statistical libraries. Solutions in .ipynb format include relevant problem notes, formulas, and examples.
NOTE: GitHub does not consistently render .ipynb files. This is a well documented issue. To workaround this issue, access the github url via nbviewer.org in the Solution 2 column.
Contains solutions to HackerRank's 10 days of statistics challenge.
Contains solutions to HackerRank's databases challenges.
Contains solutions to HackerRank's databases Relational Algebra challenges.
relational algebra is to provide a theoretical foundation for relational databases, particularly query languages for such databases, chief among which is SQL. Relational databases store tabular data represented as relations. Queries over relational databases often likewise return tabular data represented as relations. The main premise of the relational algebra is to define operators that transform one or more input relations to an output relation.
Number | Challenge | Score | Difficulty | Rate | Solution |
---|---|---|---|---|---|
1 | Basics of Sets and Relations #1 | 5 | ⭐ | 90.73% | md |
2 | Basics of Sets and Relations #2 | 5 | ⭐ | 97.48% | md |
3 | Basics of Sets and Relations #3 | 5 | ⭐ | 97.40% | md |
4 | Basics of Sets and Relations #4 | 5 | ⭐ | 96.91% | md |
5 | Basics of Sets and Relations #5 | 5 | ⭐ | 97.79% | md |
6 | Basics of Sets and Relations #6 | 5 | ⭐ | 97.02% | md |
7 | Basics of Sets and Relations #7 | 5 | ⭐ | 98.24% | md |
8 | Relational Algebra - 3 | 2 | MC | 67.45% | md |
9 | Relational Algebra - 4 | 2 | MC | 62.70% | md |
10 | Database Query Languages | 2 | MC | 84.37% | md |
11 | Procedural Language | 2 | MC | 46.76% | md |
12 | Relations - 1 | 2 | MC | 68.18% | md |
13 | Relations - 2 | 2 | MC | 74.00% | md |
Contains solutions to Indexes.
A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure.
Number | Challenge | Score | Difficulty | Rate | Solution |
---|---|---|---|---|---|
1 | Index Architecture Types | 2 | - | 61.20% | md |
2 | Indexes - 2 | 2 | MC | 51.46% | md |
3 | Indexes - 3 | 2 | MC | 50.44% | md |
4 | Indexes - 4 | 2 | MC | 69.61% | md |
Contains solutions to HackerRank's OLAP challenges.
Online analytical processing is an approach to answer multi-dimensional analytical (MDA) queries swiftly in computing. OLAP is part of the broader category of business intelligence, which also encompasses relational databases, report writing and data mining. OLAP tools enable users to analyze multidimensional data interactively from multiple perspectives
Number | Challenge | Score | Difficulty | Rate | Solution |
---|---|---|---|---|---|
1 | OLAP Performance | 5 | - | 74.77% | md |
2 | OLAP Operations - 1 | 5 | MC | 43.92% | md |
3 | OLAP Operations - 2 | 5 | MC | 65.58% | md |
4 | OLAP Cube Metadata | 5 | MC | 63.26% | md |
5 | OLAP Name(s) | 5 | MC | 60.87% | md |
6 | The Total View | 5 | MC | 55.59% | md |
Contains solutions to Set and Algebra.
Number | Challenge | Score | Difficulty | Rate | Solution |
---|---|---|---|---|---|
1 | Databases - Relational Calculus | 5 | ⭐⭐ | 84.56% | md |
2 | Databases - Keys | 5 | ⭐⭐ | 97.91% | md |
3 | Databases - Natural Joins | 5 | ⭐⭐ | 95.39% | md |
4 | Databases - Differences | 5 | ⭐⭐ | 96.96% | md |
Contains solutions to HackerRank's python challenges using Python3.
Contains solutions to introduction.
Number | Challenge | Score | Difficulty | Rate | Solution |
---|---|---|---|---|---|
1 | Say "Hello, World!" With Python | 5 | ⭐ | 97.62% | py |
2 | Python If-Else | 10 | ⭐ | 91.31% | py |
3 | Arithmetic Operators | 10 | ⭐ | 98.44% | py |
4 | Python: Division | 10 | ⭐ | 98.87% | py |
5 | Loops | 10 | ⭐ | 98.48% | py |
6 | Write a function | 10 | ⭐⭐ | 90.61% | py |
7 | Print Function | 20 | ⭐ | 96.50% | py |
Contains solutions to Basic Data Types.
Number | Challenge | Score | Difficulty | Rate | Solution |
---|---|---|---|---|---|
1 | List Comprehensions | 10 | ⭐ | 98.27% | py |
2 | Find the Runner-Up Score! | 10 | ⭐ | 93.80% | py |
3 | Nested Lists | 10 | ⭐ | 90.65% | py |
4 | Finding the percentage | 10 | ⭐ | 97.34% | py |
6 | Tuples | 10 | ⭐ | 98.40% | py |
Contains solutions to Strings.
Number | Challenge | Score | Difficulty | Rate | Solution |
---|---|---|---|---|---|
1 | sWAP cASE | 10 | ⭐ | 98.63% | py |
2 | String Split and Join | 10 | ⭐ | 98.88% | py |
3 | What's Your Name? | 10 | ⭐ | 97.87% | py |
4 | Mutations | 10 | ⭐ | 98.54% | py |
5 | Find a string | 10 | ⭐ | 93.24% | py |
6 | String Validators | 10 | ⭐ | 93.34% | py |
7 | Text Alignment | 10 | ⭐ | 97.67% | py |
8 | Text Wrap | 10 | ⭐ | 98.74% | py |
9 | Designer Door Mat | 10 | ⭐ | 98.28% | py |
10 | String Formatting | 10 | ⭐ | 90.21% | py |
11 | Alphabet Rangoli | 20 | ⭐ | 96.74% | py |
12 | Capitalize! | 20 | ⭐ | 82.59% | py |
13 | The Minion Game | 40 | ⭐⭐ | 85.06% | py |
14 | Merge the Tools! | 40 | ⭐⭐ | 92.11% | py |
Contains solutions to Sets.
Number | Challenge | Score | Difficulty | Rate | Solution |
---|---|---|---|---|---|
1 | Introduction to Sets | 10 | ⭐ | 98.51% | py |
2 | No Idea! | 50 | ⭐⭐ | 85.81% | py |
3 | Symmetric Difference | 10 | ⭐ | 97.89% | py |
4 | Set .add() | 10 | ⭐ | 99.18% | py |
5 | Set .discard(), .remove() & .pop() | 10 | ⭐ | 96.32% | py |
6 | Set .union() Operation | 10 | ⭐ | 99.19% | py |
7 | Set .intersection() Operation | 10 | - | 99.51% | py |
8 | Set .difference() Operation | 10 | - | 99.41% | py |
9 | Set .symmetric_difference() Operation | 10 | ⭐ | 99.50% | py |
10 | Set Mutations | 10 | ⭐ | 98.24% | py |
11 | The Captain's Room | 10 | ⭐ | 89.99% | py |
12 | Check Subset | 10 | ⭐ | 98.65% | py |