Remove Duplicates from Sorted List

Welcome to a comprehensive guide on removing duplicates from a sorted list! This tutorial is designed to help both beginners and intermediates learn and understand the concept effectively. Let's get started!

Understanding the Problem

In a sorted list, the elements are in a specific order, usually ascending or descending. However, sometimes, we might have duplicates that we want to eliminate for various reasons, such as improving efficiency or reducing storage space.

📝 Note: Eliminating duplicates is an essential data manipulation operation in many real-world scenarios, like filtering data in databases, optimizing search algorithms, and more.

Solution Approaches

There are multiple ways to remove duplicates from a sorted list, but we'll focus on two common methods:

Iterative Method
One-Pass Linear Method

Iterative Method

This method uses an auxiliary data structure to store unique elements. Here's how it works:

🎯 Steps:

Initialize an empty list to store unique elements.
Iterate through the sorted list.
For each element, check if it already exists in the unique list. If it doesn't, append it to the unique list.
After iterating through the entire list, the unique list will only contain unique elements.

Here's a Python example:

python

def remove_duplicates(input_list):
    unique_list = []
    for num in input_list:
        if num not in unique_list:
            unique_list.append(num)
    return unique_list

Quick Quiz

Question 1 of 1

What does the Iterative Method use for storing unique elements?

One-Pass Linear Method

This method modifies the original sorted list by removing duplicates in a single pass. Here's how it works:

🎯 Steps:

Initialize a variable to keep track of the current unique element.
Iterate through the sorted list.
If the current element is different from the last unique element, append it to the unique list.
After iterating through the entire list, the first part of the list will only contain unique elements.

Here's a Python example:

python

def remove_duplicates(input_list):
    unique_list = []
    for num in input_list:
        if num != unique_list[-1] and num not in unique_list:
            unique_list.append(num)
    return unique_list

Quick Quiz

Question 1 of 1

What does the One-Pass Linear Method use to store unique elements?

Wrapping Up

Congratulations! You've learned two methods to remove duplicates from a sorted list. Remember, the Iterative Method uses an auxiliary list, while the One-Pass Linear Method modifies the original list.

These techniques can be used in various programming languages and are valuable skills for any developer. Keep practicing, and happy coding! 🎉