Removing Duplicate elements from an array
Detailed guide and Python implementation for the 'Removing Duplicate elements from an array' problem.
1. Concept Overview
The 'Removing Duplicate elements from an array' problem is a key challenge in the Arrays section.
This implementation focuses on easy-level logic in Python.
We prioritize technical accuracy and code readability in our provided solutions.
2. Real-World Applications
3. Visual Intuition
Visualizing the logic flow for Removing Duplicate elements from an array.
4. Prerequisites
5. Step-by-Step Thinking
1. Understand the problem
Read the problem statement for Removing Duplicate elements from an array carefully.
2. Formulate brute force
Draft a simple iterative solution.
3. Identify inefficiency
Look for redundant calculations.
4. Optimize search path
Use hashing or sorting to speed up the process.
5. Final Implementation
Clean up the code for production standards.
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?
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Interview Insights & Variations
Complexity Analysis Breakdown
Why Time: Directly evaluates all possibilities.
Why Space: Uses standard local memory.
Why Time: Optimized paths reduce total operations.
Why Space: May trade memory for speed.
Optimized Solution Python Code
Optimized Solution Python Code
def remove_duplicates_opt(arr):
# preserves order in Python 3.7+
return list(dict.fromkeys(arr))Brute Force Code (Spoiler Guarded)
Brute Force Code (Spoiler Guarded)
def remove_duplicates_brute(arr):
res = []
for num in arr:
if num not in res:
res.append(num)
return resAlgorithm Pattern Checklist
When dealing with Arrays data patterns.
Core Prerequisites
Revision Key Notes
Common Mistakes & Pitfalls
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