Removing Duplicate elements from an array
Detailed guide and Python implementation for the 'Removing Duplicate elements from an array' problem.
Problem Statement
Write a function remove_duplicates(arr) that takes a list of integers arr and returns a new list with duplicate elements removed, preserving the order of first occurrence of each element.
- •0 <= len(arr) <= 10^5
- •-10^6 <= arr[i] <= 10^6
Examples
arr = [1, 2, 2, 3, 4, 4, 5]
[1, 2, 3, 4, 5]
Remove the second 2 and second 4, keeping first occurrences in order.
arr = [5, 5, 5, 5]
[5]
All duplicates removed, keeping only one 5.
arr = [1, 2, 3]
[1, 2, 3]
No duplicates, array unchanged.
Need a Hint?
Edge Cases to Watch
- Empty input structures
- Single element inputs
- Large numerical bounds
Ready to Solve?
Open the problem in PyRun's browser-based Python editor. Your code runs fully offline — no server required.
Recommended Python Resources
Expand your knowledge with related interactive tutorials, cheat sheets, and code comparisons.
Python Try/Except & Error Handling
Prevent your Python scripts from crashing. Learn try, except, finally blocks and how to raise custom exceptions properly.
How to Remove Duplicates From a List in Python
Learn how to remove duplicates from a list in Python while maintaining or ignoring order. Compare set conversions, dict keys, and loop methods.
Python pip Package Manager
Command-line reference guide for pip. Learn to install, upgrade, uninstall, and manage Python packages and dependencies.
Python vs JavaScript: Which Programming Language is Best?
A comprehensive comparison between Python and JavaScript. Explore syntax differences, performance, use cases (backend vs frontend), and coding examples.