🎉 Introducing: Challenge Series 🧑‍💻

Hello, developers! 🚀

We’re excited to announce the launch of our Challenge Series! 🎯

This series is designed to sharpen your coding skills, boost your problem-solving abilities, and help you dive deeper into the world of programming. Whether you’re just starting out or you’re a seasoned developer, these challenges will push you to think critically and write efficient code.

🔍 What to Expect:

- Weekly Challenges: Every week, we’ll post a new coding challenge that covers a variety of topics—from algorithms and data structures to practical Swift problems you might encounter in real-world projects.
- Detailed Solutions: After you’ve had time to tackle the challenge, we’ll provide a solution breakdown, explaining the most optimal approaches and why they work.
- Community Discussions: Share your solutions, discuss different approaches, and learn from each other! This series is all about growing together.

🏅 Why Participate?

- Improve Your Skills: Regularly solving coding problems is one of the best ways to level up your programming skills.
- Get Interview Ready: These challenges are designed to prepare you for technical interviews, focusing on the types of problems you might face.
- Join a Community: Engage with fellow developers, exchange ideas, and grow your network!

Stay tuned, and let’s get coding! 💻

📝 #challenge N1: #medium level.

Find the Majority Element.

🔍 Problem Statement:
Given an array of integers, find the majority element. The majority element is the one that appears more than half the time in the array. You may assume that the array is non-empty and that the majority element always exists in the array.

💡 Example:
let input = [3, 2, 3]
let result = findMajorityElement(input)
print(result) // Output: 3

another example:
let input = [2, 2, 1, 1, 1, 2, 2]
let result = findMajorityElement(input)
print(result) // Output: 2

🔧 Function Signature:
func findMajorityElement(_ nums: [Int]) -> Int {
// Your code here
}

🚀 Constraints:
The input array will contain at least one element.
The majority element always exists in the array.

🏅 Objective:
Solve this challenge using the most optimal approach you can think of.
Share your solution and discuss different approaches in the comments!

you can use online playground, take screenshot.
https://www.mycompiler.io/new/swift

Please don't cheat!✋
Happy coding! 🎯

@software_efficiency

📝 #solution N1

Explanation:
- Boyer-Moore Voting Algorithm works by maintaining a candidate for the majority element and a counter.
- We iterate through the array:
-- If the count is zero, we set the current element as the candidate.
-- For each element, we either increase the count (if it matches the candidate) or decrease it (if it doesn't).
- By the end of the iteration, the candidate will be the majority element.

This solution is optimal as it uses O(n) time complexity and O(1) space, which meets the challenge requirements for efficiency.

You can try running it on the playground: https://www.mycompiler.io/new/swift.

Let me know if you'd like to discuss other approaches or any improvements!

@software_efficiency

📝 #challenge N2: #medium level.

Find All Duplicates in an Array

🔍 Problem Statement: Given an integer array nums of length n where all integers are in the range [1, n], find all the integers that appear twice in the array. The solution must run in O(n) time and use only constant extra space.

💡 Example:
let input = [4,3,2,7,8,2,3,1]
let result = findDuplicates(input)
print(result)
// Output: [2, 3]

🔧 Function Signature:
func findDuplicates(_ nums: [Int]) -> [Int] {
// Your code here
}

🚀 Constraints:
The array contains integers in the range [1, n], where n is the length of the array.
Some elements appear twice and others appear once.

🏅 Objective: Solve this problem using O(n) time and O(1) space complexity, meaning you must modify the input array in-place. Share your solution and discuss different approaches in the comments!

You can use the online playground: https://www.mycompiler.io/new/swift

Happy coding! 🎯

📝 #solution #2

This solution runs in O(n) time and uses O(1) extra space by modifying the array in place. It works by using the indices of the array to mark the presence of each number. When we encounter a number that has already been marked negative, we know it's a duplicate.

@software_efficiency

📝 #challenge #3: easy.

Find the Missing Number

🔍 Problem Statement: Given an array nums containing n distinct numbers in the range [0, n], find the one number that is missing from the array. Your solution should run in O(n) time and use O(1) extra space.

💡 Example:
let nums = [3, 0, 1]
let result = missingNumber(nums)
print(result)
// Output: 2

🔧 Function Signature:
func missingNumber(_ nums: [Int]) -> Int {
// code here
}

The array contains n distinct numbers in the range [0, n].

Solve this problem using a mathematical formula or bit manipulation to find the missing number. Share your solution and discuss different approaches in the comments!

You can use the online playground: https://www.mycompiler.io/new/swift

Happy coding! 🎯

@software_efficiency

The journey of a thousand miles begins with one step.

a Chinese philosopher.

📝 #solution #3

Explanation:
- The formula n * (n + 1) / 2 gives the sum of numbers from 0 to n.
- nums.reduce(0, +) calculates the sum of the elements in the array.
- The missing number is simply the difference between the expected sum and the actual sum.

* the array should contain n distinct numbers in the range [0, n]. Otherwise, the algorithm won't work as expected because it's designed for a specific kind of input.

@software_efficiency

Software Engineer ≠ Developer 🔍
Software Engineer = Problem Solver 💡

Here’s the truth no one tells you when you start writing code:
Great engineers don’t just jump into coding.

They start by solving the problem,
without writing a single line.

Why?
Because code is a liability.
Every line you write = something you’ll maintain, debug, and defend in production later.

The best engineers I’ve worked with all do the same thing:
Understand the problem deeply
Zoom out - what’s the business need?
Zoom in - what’s the simplest solution?
Only then… they start to code (if needed)

✨ Sometimes the best solution is:
✅ Changing a config
✅ Sending a manual email
✅ Updating a process
✅ Saying “no”

This is the mindset shift:
👨‍💻 Developer: “Cool, I’ll build a noscript for that.”
🧠 Engineer: “Wait… do we even need to build anything at all?”

💬 I tell every junior dev I mentor:
“Before you write code, write the logic.
If you can’t explain the solution in plain English, don’t explain it in Swift.”

@software_efficiency

Simple Modularization setup for a New App
  
This article introduces a simple modularization setup for new iOS apps using Swift Package Manager and local packages.

It explains the benefits of modularization, outlines a basic project structure with Core, Domain, and Presentation layers, and offers practical tips for managing dependencies and scaling the approach as the app grows.