DEV Community: junian

Using Touch ID for sudo on Mac

junian — Wed, 30 Sep 2026 16:00:00 +0000

This article was originally posted at junian.dev. A video with the same content is also available on YouTube

Touch ID is one of the greatest things on my MacBook.
I can authenticate a lot of stuff just by resting my finger on it.
I can log in to any website using either passkey or the built-in password manager quickly too.

I wish I could use it from Terminal though.
It would be super convenient if I could use Touch ID to authenticate sudo when executing a terminal command.

By default, macOS will ask for your password whenever you execute a command with sudo.
But did you know that macOS actually supports Touch ID to authenticate sudo?
I didn't know, but the feature is there.
You just need to update the config file.

Video
Enabling Touch ID for sudo on macOS 14 Sonoma or later
Enabling Touch ID for sudo on macOS 13 Ventura or earlier
Enabling Touch ID for sudo using mole
Final Thoughts

Video

Not in the mood for reading? Watch the video instead.

Enabling Touch ID for sudo on macOS 14 Sonoma or later

The solution is quite simple.

On macOS 14 (Sonoma) and later, there is a template file ready to use.
The template is located at /etc/pam.d/sudo_local.template.
Here's the content of the file on my macOS 27 Golden Gate:

$ cat /etc/pam.d/sudo_local.template
# sudo_local: local config file which survives system update and is included for sudo
# uncomment following line to enable Touch ID for sudo
#auth       sufficient     pam_tid.so

To enable Touch ID for sudo, copy the template file into sudo_local.

sudo cp /etc/pam.d/sudo_local.template /etc/pam.d/sudo_local

We need to edit the sudo_local file.
You can use vim or any other text editor to do it.

sudo -E vim /etc/pam.d/sudo_local

All we need to do is to uncomment the 3rd line and save the file.
The final /etc/pam.d/sudo_local file will look like this:

# sudo_local: local config file which survives system update and is included for sudo
# uncomment following line to enable Touch ID for sudo
auth       sufficient     pam_tid.so

Once it's done, open a new Terminal session and test it.
Execute something with sudo, you can try something simple like:

sudo ls -lah ~

This time, a Touch ID dialog will show up, and you can authenticate it using your fingerprint instead of entering your password manually.

Enabling Touch ID for sudo on macOS 13 Ventura or earlier

To use Touch ID to authenticate sudo on macOS 13 Ventura or older, you need to edit the /etc/pam.d/sudo file.

Just for reference, here's the default content on my macOS 27 Golden Gate (might differ for each macOS version).

$ cat /etc/pam.d/sudo
# sudo: auth account password session
auth       include        sudo_local
auth       sufficient     pam_smartcard.so
auth       required       pam_opendirectory.so
account    required       pam_permit.so
password   required       pam_deny.so
session    required       pam_permit.so

Now let's add a new config that will use Touch ID to authenticate sudo.
Open Terminal.app and edit using vim or any other text editor.
You need to use sudo to edit the file.

sudo -E vim /etc/pam.d/sudo

Add the following line at the top of the config file.

auth       sufficient     pam_tid.so

Save the new changes. In my case, the new /etc/pam.d/sudo config will look like this:

auth       sufficient     pam_tid.so
auth       include        sudo_local
auth       sufficient     pam_smartcard.so
auth       required       pam_opendirectory.so
account    required       pam_permit.so
password   required       pam_deny.so
session    required       pam_permit.so

Once it's done, open a new Terminal session and test it.
Execute something with sudo, you can try something simple like:

sudo ls -lah ~

This time, a Touch ID dialog will show up, and you can authenticate it using your fingerprint instead of entering your password manually.

NOTE: /etc/pam.d/sudo is a default macOS file, so it will be overwritten by system updates. You need to re-apply this change after each time you update macOS.

Enabling Touch ID for sudo using mole

Another alternative is to use mole to configure Touch ID for sudo.
You can first install mole using brew.

brew install mole

Then execute the following command and follow the instructions.

mo touchid

That's it, mole will add the configuration automatically, similar to the manual methods above.

Final Thoughts

That's all I can write for today.
Thanks for reading, and see you in my next post.

How to Delete All OpenCode Sessions

junian — Sat, 29 Aug 2026 23:30:00 +0000

This article was originally published at Junian Dev Blog

I've been using OpenCode a lot lately.
One thing I didn't notice was that every time I start opencode, even in the same directory, it always starts a new session.
Over time, there are a lot of saved sessions.

I checked using the opencode session list command and it has a bunch of sessions like this:

$ opencode session list
Session ID                      Title                                   Updated
────────────────────────────────────────────────────────────────────────────────────────────
ses_01a79c031ffeoTF781ma9DAYiR  New session - 2026-08-09T07:56:48.462Z  10:14 PM ·  8/9/2026
ses_02142df4bffeJZJCNI2flGgZiw  New session - 2026-08-08T00:19:24.468Z   7:07 AM ·  8/9/2026
ses_03051a679ffe7LNdjOeQQs8hC8  New session - 2026-08-05T02:08:57.735Z   9:10 AM ·  8/5/2026
ses_03fb4423effeJSOWB6yROH3mzp  New session - 2026-08-02T02:26:57.089Z   9:35 AM ·  8/2/2026
ses_25fdf08f1ffetxmcBDVYGfI1Me  Code functionality review                5:33 PM · 4/18/2026
ses_260544176ffe1iW1RyEcxgz102  Codebase review                          3:20 PM · 4/18/2026

One beautiful day, I wanted to start a project with a fresh, clean slate.
No existing session should be available.
So what I had to do was to delete all sessions.

Unfortunately, opencode didn't have (yet) a way to delete all sessions in one command.
You can only delete a single session like this:

opencode session delete $sessionID

But, with the power of the command line, you can still delete all opencode sessions using a one-line terminal command.

To make it work, you need to install the jq command line first.
For example, you can install jq on macOS with the Homebrew package manager like this:

brew install jq

Then, here's how to remove all opencode sessions with a one-line command:

opencode session list --format json \
  | jq -r '.[].id' \
  | xargs -r -n1 opencode session delete

Basically, you just need to list the OpenCode's sessions in JSON format, extract all the IDs using jq, and execute the standard opencode session delete.

That's it.
Now you can always fresh clean up your opencode sessions easily from Terminal.

As usual, if you have any questions or a better method, leave a comment below.
Thanks for reading, and see you next time!

Installing Multiple .NET Versions on macOS with Homebrew

junian — Wed, 01 Oct 2025 02:25:59 +0000

This article was originally published at Junian Dev Blog

If you're a .NET developer using macOS, you may want to install multiple .NET SDK versions side by side.
While you can do this manually, it can become a headache to maintain in the long term. As you install more SDKs, leftover files can accumulate and fill up your storage.

Uninstalling older versions manually can also be tedious. You can refer to the official documentation for removal instructions. I even wrote an uninstallation guide to remind myself how to do it properly.

A more elegant solution is to use the Homebrew package manager to manage .NET SDK installations on macOS.

However, the official Homebrew cask for .NET does not allow multiple SDK versions to be installed at the same time. When you install one version, it prevents you from using others.

This can be problematic if you need to work on projects that require different .NET versions. While upgrading projects to the latest .NET version is often ideal, sometimes it's not feasible.

Solution

To address this, I created a dedicated Homebrew tap for .NET.

Using it is simple.

Before using this Homebrew .NET tap, first uninstall any existing dotnet-sdk formula from the core Homebrew cask if you have it installed:

brew uninstall --zap dotnet-sdk

Once that's done, tap my repository:

brew tap junian/homebrew-dotnet

For example, to install the .NET 10 SDK:

brew install dotnet-sdk@10.0

That's it! Now you can use .NET 10 on your macOS system.

Let's consider a scenario:

Suppose a client needs a bug fix for a project that still uses .NET 6.0. You can install it with:

brew install dotnet-sdk@6.0

Now you can use .NET 6.0 to work on that project.

Later, if the client wants to migrate to .NET 9, you can install it as well:

brew install dotnet-sdk@9.0

When you no longer need .NET 6.0, simply remove it:

brew uninstall dotnet-sdk@6.0

You'll still have .NET 9 and .NET 10 installed on your macOS. It's that easy!

Conclusion

That's all for today. I hope this simple guide helps you manage .NET SDKs on your macOS.

For more details, check out the documentation for the Homebrew .NET tap.

If you have any questions or suggestions, feel free to leave a comment below.

Thanks for reading, and see you next time!

References

junian/homebrew-dotnet: Install .NET SDK side-by-side on macOS with Homebrew package manager.

Troubleshooting Flutter Android App to Target SDK 35 Upgrade

junian — Mon, 29 Sep 2025 18:31:42 +0000

This article was originally published at Junian Dev Blog

Another year, another chore: upgrading the Android app target SDK. This year, Google requires Target SDK 35.

So, here’s my experience upgrading an existing Flutter Android app. There were a few issues, but every problem has a solution.

Note: At the time of writing this tutorial, I was using Flutter v3.10.6.

Set Target SDK to 35

First, update the Android target SDK version manually by editing the android/local.properties file:

-flutter.compileSdkVersion=34
+flutter.compileSdkVersion=35
-flutter.targetSdkVersion=34
+flutter.targetSdkVersion=35
 flutter.minSdkVersion=21
 flutter.ndkVersion=26.1.10909125

After updating, build the Android bundle:

flutter build appbundle

As expected, some issues appeared.

Update Gradle to 8.5

The first error was RES_TABLE_TYPE_TYPE entry offsets overlap actual entry data.

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:processReleaseResources'.
> A failure occurred while executing com.android.build.gradle.internal.res.LinkApplicationAndroidResourcesTask$TaskAction
   > Android resource linking failed
     aapt2 E 09-30 01:01:15 26752 18645483 LoadedArsc.cpp:94] RES_TABLE_TYPE_TYPE entry offsets overlap actual entry data.
     aapt2 E 09-30 01:01:15 26752 18645483 ApkAssets.cpp:149] Failed to load resources table in APK '/opt/homebrew/share/android-commandlinetools/platforms/android-35/android.jar'.
     error: failed to load include path /opt/homebrew/share/android-commandlinetools/platforms/android-35/android.jar.

This happened because I was still using Gradle v7.3. Upgrade to at least v8.5 (I chose v8.9):

cd android/
./gradlew wrapper --gradle-version=8.9

Then update the Gradle plugin version in android/build.gradle:

dependencies {
-    classpath 'com.android.tools.build:gradle:7.3.0'
+    classpath 'com.android.tools.build:gradle:8.5.0'
    // ...
}

Rebuild the app after updating.
Naturally, another issue came up. No surprises there.

Flutter In-App WebView Issue

Next, an error related to :flutter_inappwebview appeared:

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring project ':flutter_inappwebview'.
> Could not create an instance of type com.android.build.api.variant.impl.LibraryVariantBuilderImpl.
   > Namespace not specified. Specify a namespace in the module's build file: /Users/junian/.pub-cache/hosted/pub.dev/flutter_inappwebview-5.8.0/android/build.gradle. See https://d.android.com/r/tools/upgrade-assistant/set-namespace for information about setting the namespace.

     If you've specified the package attribute in the source AndroidManifest.xml, you can use the AGP Upgrade Assistant to migrate to the namespace value in the build file. Refer to https://d.android.com/r/tools/upgrade-assistant/agp-upgrade-assistant for general information about using the AGP Upgrade Assistant.

Based on this Stack Overflow answer, add the following subprojects section to android/build.gradle:

// ...

subprojects {
    afterEvaluate { project ->
        if (project.hasProperty('android')) {
            project.android {
                if (namespace == null) {
                    namespace project.group
                }
            }
        }
    }
}

// ...

The journey was not over. There were more issues ahead.

Java 8 Desugaring Support

If your project uses Java 8, you may see:

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:checkReleaseAarMetadata'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.CheckAarMetadataWorkAction
   > An issue was found when checking AAR metadata:

       1.  Dependency ':flutter_local_notifications' requires core library desugaring to be enabled
           for :app.

           See https://developer.android.com/studio/write/java8-support.html for more
           details.

Enable desugaring by setting coreLibraryDesugaringEnabled to true and adding the dependency in android/app/build.gradle:

android {
    // ...

    compileOptions {
        coreLibraryDesugaringEnabled true
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    // ...
}

// ...

dependencies {
    // ...

    coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:2.0.3'
}

One final problem ahead!

Kotlin Version Update

Another issue when building the Android bundle was something to do with Kotlin version.

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:compileReleaseKotlin'.
> A failure occurred while executing org.jetbrains.kotlin.compilerRunner.GradleCompilerRunnerWithWorkers$GradleKotlinCompilerWorkAction
   > Compilation error. See log for more details

At the end of the error message, there was a note:

[!] Your project requires a newer version of the Kotlin Gradle plugin.                                                                                             │
Find the latest version on https://kotlinlang.org/docs/releases.html#release-details, then update /Users/junian/Projects/flutter-app/android/build.gradle: 
ext.kotlin_version = '<latest-version>'

The solution was to update the Kotlin version from v1.7 to v1.9 in the buildscript section of android/build.gradle:

buildscript {
-    ext.kotlin_version = '1.7.10'
+    ext.kotlin_version = '1.9.25'
}

Let's see if there was another bug to smash.

Final Build. Finally!

With all fixes applied, I could finally build the Android bundle successfully:

$ flutter build appbundle
Running Gradle task 'bundleRelease'...                             52.0s
✓ Built build/app/outputs/bundle/release/app-release.aab (39.7MB).

I submitted the new .aab release to Google Play and waiting for review.

Conclusion

Thanks for reading! I hope your upgrade to Android Target SDK 35 goes smoothly.

If you have questions or want to discuss, feel free to leave a comment below.

Thank you and see you next time!

References

Solving the Xamarin.Forms iOS 'Could Not Load the Framework IDEDistribution' Issue

junian — Thu, 13 Feb 2025 09:03:36 +0000

This article was originally published at Junian Dev Blog

Xamarin.Forms is deprecated as of May 2024. I get it.
But some of us are still trying to maintain legacy Xamarin projects.

It's 2025, and I tried to run a Xamarin.Forms iOS project with the latest Xcode version on macOS.
It failed with the following error message.

error HE0004: Could not load the framework 'IDEDistribution' (path: /Applications/Xcode.app/Contents/SharedFrameworks/IDEDistribution.framework/Versions/A/IDEDistribution):
dlopen(/Applications/Xcode.app/Contents/SharedFrameworks/IDEDistribution.framework/Versions/A/IDEDistribution, 0x0001): Library not loaded: @rpath/AppThinning.framework/Versions/A/AppThinning
Referenced from: <6F88EF9E-AE57-3231-9DD6-36E9CC59D914> /Applications/Xcode.app/Contents/SharedFrameworks/IDEDistribution.framework/Versions/A/IDEDistribution
Reason: tried: '/Library/Frameworks/Xamarin.iOS.framework/Versions/16.4.0.23/lib/mlaunch/mlaunch.app/Contents/Frameworks/AppThinning.framework/Versions/A/AppThinning' (no such file), '/Applications/Xcode.app/Contents/SharedFrameworks/IDEDistribution.framework/Versions/A/Frameworks/AppThinning.framework/Versions/A/AppThinning' (no such file), '/Library/Frameworks/Xamarin.iOS.framework/Versions/16.4.0.23/lib/mlaunch/mlaunch.app/Contents/Frameworks/AppThinning.framework/Versions/A/AppThinning' (no such file), '/Applications/Xcode.app/Contents/SharedFrameworks/IDEDistribution.framework/Versions/A/Frameworks/AppThinning.framework/Versions/A/AppThinning' (no such file), '/Library/Frameworks/Xamarin.iOS.framework/Versions/16.4.0.23/lib/mlaunch/mlaunch.app/Contents/MonoBundle/AppThinning.framework/Versions/A/AppThinning' (no such file)

The latest Xamarin.iOS version is 16.4.0.23.
There are no more updates, and I guess it's incompatible with Xcode 16.

Luckily, the solution is simple.

First, go to the Xamarin.iOS.framework directory, specifically to the mlaunch.app directory.

cd /Library/Frameworks/Xamarin.iOS.framework/Versions/16.4.0.23/lib/mlaunch/mlaunch.app/Contents

Create a new directory called Frameworks.

sudo mkdir Frameworks

Then, copy the AppThinning.framework from Xcode to the newly-created Frameworks directory.

sudo cp -r /Applications/Xcode.app/Contents/SharedFrameworks/AppThinning.framework ./Frameworks

That's it! Now you can build and run your Xamarin.iOS app again.

References

Could not load the framework IDEDistribution on MacOS 15.0 : RIDER-117599

How to Fix 'File Access Denied' Issue on Windows

junian — Thu, 21 Nov 2024 07:04:14 +0000

Have you ever tried to delete or move a file in Windows File Explorer, only to encounter an error message like this?

File Access Denied

You need permission to perform this action.

You require permission from PC-NAME\username to make changes to this file.

You're not alone, and here's how to resolve it:

Right-click the file and select Properties.
Navigate to the Security tab and click the Advanced button.
Click the Change button next to the Owner field.
Enter your username, click Check Names to verify it, then click OK.
In the Permissions tab, click Add to assign full control permission.
Click Select a principal; a new dialog box will appear.
Enter your username again, click Check Names to verify, then click OK.
Back in the Permission Entry dialog, check the Full control permission.
Click OK on all dialogs to apply the changes.

Once you complete these steps, you should be able to modify, delete, or move the file.

Here's a video to help visualize the process:

Thanks for reading. I hope you found this helpful. See you next time!

How to Run Safari Browser without CORS Restriction

junian — Sun, 17 Nov 2024 04:28:56 +0000

As a web developer, you likely need to test your REST API locally. When using a browser like Safari, you might encounter issues such as the following messages.

Origin http://localhost:8081 is not allowed by Access-Control-Allow-Origin. Status code: 200

Fetch API cannot load http://localhost:8080/api/ due to access control checks.

Failed to load resource: Origin http://localhost:8081 is not allowed by Access-Control-Allow-Origin. Status code: 200

Don't worry, this is actually a strong security feature implemented by modern web browsers.

I won't overwhelm you with details about CORS—you can read more in the official documentation. However, if you're interested, here's a summary from Wikipedia.

Cross-origin resource sharing (CORS) is a mechanism to safely bypass the Same-origin policy, that is, it allows a web page to access restricted resources from a server on a domain different than the domain that served the web page.

Here's an example of a cross-origin request: the front-end JavaScript code served from https://example.com/ uses fetch() to request https://example.org/api/data.json.

Luckily, bypassing CORS restrictions in Safari is straightforward.

Solution to Disable CORS in Safari

Click on Safari in the top menu bar and select Settings....
Go to the Advanced tab and check the Show features for web developers option.
A new Developer tab will appear.
Select Developer tab and enable the Disable cross-origin restrictions option.
Return to Safari and refresh the page. It should work now!

Video

Here is the video to visualize the steps above.

Conclusion

Disabling CORS on Safari through the settings is quite simple.
I do wish there were a command-line solution, but let's be grateful for any method available.

Thanks for reading, and see you around!

412. Fizz Buzz | LeetCode in C#

junian — Thu, 14 Nov 2024 05:01:57 +0000

The Fizz Buzz problem is a classic exercise that is often used to teach basic programming concepts such as loops and conditionals.

In this article, I'll show you my attempt to solve this problem.

Intuition

When breaking down the problem, the task is to iterate through a sequence of numbers while applying simple divisibility rules to determine the correct output for each number.

The logic is straightforward: replace numbers with specific words based on their divisibility.

Approach

To solve the Fizz Buzz problem, we can use a simple loop and a series of conditional checks:

Initialize a List: Start by creating a list to store the results.
Iterate through Numbers: Loop through numbers from 1 to n.
Check Divisibility:
- If a number is divisible by both 3 and 5, it should be labeled "FizzBuzz".
- Else, if it's divisible by 3, label it "Fizz".
- Else, if it's divisible by 5, label it "Buzz".
- If none of these conditions are met, add the number itself as a string.
Add to List: For each number, append the appropriate label or number to the results list.
Return the Result: Finally, return the list containing all the strings.

Complexity

Time complexity: The time complexity is O(n) because we process each number from 1 to n exactly once.
Space complexity: The space complexity is O(n) because we store a string result for each number in the

Code

public class Solution {
    public IList<string> FizzBuzz(int n) {
        var result = new List<string>{};
        for(var i = 1; i <= n; i++)
        {
            if(i % 3 == 0 && i % 5 == 0)
            {
                result.Add("FizzBuzz");
            }
            else if(i % 3 == 0)
            {
                result.Add("Fizz");
            }
            else if(i % 5 == 0)
            {
                result.Add("Buzz");
            }
            else
            {
                result.Add(i.ToString());
            }
        }
        return result;
    }
}

Video

Conclusion

This approach provides an efficient way to implement the Fizz Buzz logic by using a loop and conditional checks.

The function generates the desired output for any valid positive integer n, allowing it to handle a wide range of input values effectively.

This solution is not only concise but also clear, making it easy to understand for anyone familiar with basic programming constructs.

This explanation captures the essence of how the Fizz Buzz problem can be addressed programmatically with a simple and clean loop-and-conditional structure.

References

Fizz Buzz - LeetCode

9. Palindrome Number | LeetCode in C#

junian — Sun, 10 Nov 2024 10:03:55 +0000

Intuition

A number is a palindrome if it reads the same forwards and backwards. The first thought might be to convert the number into a string and check if it matches its reverse. However, the challenge is to solve this without converting the integer to a string, which calls for a numerical approach.

Approach

To determine if an integer is a palindrome without using string conversion, we reverse the integer by repeatedly extracting its last digit and appending it to a new reversed number. Here's how:

Negative Numbers: Start by handling negative numbers. Any negative number cannot be a palindrome since the negative sign only appears on one side.
Reverse Integer: Initialize reverseNumber to zero and a copy of the input x called y. While y is greater than zero, repeatedly:
- Extract the last digit (y % 10) from y and append it to reverseNumber by multiplying reverseNumber by 10 and adding the digit.
- Remove the last digit from y by performing integer division by 10.
Comparison: After constructing the reversed integer, compare it to the original number x. If they are identical, x is a palindrome.

This approach effectively reconstructs the reversed number without needing the original number's length or auxiliary string manipulations.

Complexity

Time complexity: The time complexity is O(log(n)) because we iterate through all the digits of the number x, where n is the input value.
Space complexity: The space complexity is O(1) as we only use a few extra variables to store numbers, regardless of the input size.

Code

public class Solution {
    public bool IsPalindrome(int x) {
        if(x < 0)
            return false;

        var reverseNumber = 0;
        var y = x;

        while(y > 0)
        {
            reverseNumber = reverseNumber * 10 + (y % 10);
            y = y / 10;
        }

        return reverseNumber == x;
    }
}

Video

Conclusion

By reversing the integer numerically, this algorithm cleverly checks for palindromes without converting the number to a string, thus adhering to the problem's constraints while maintaining an efficient space complexity. This method ensures that we can handle large integers within the problem's constraints effectively.

This discussion provides a clear understanding of how to determine if a number is a palindrome via integer arithmetic, avoiding the pitfalls of converting to a string.

References

Palindrome Number - LeetCode

26. Remove Duplicates From Sorted Array | LeetCode in C#

junian — Sat, 09 Nov 2024 07:46:13 +0000

This post is a journal about how I solved the Remove Duplicates from Sorted Array problem from LeetCode.

Intuition

The problem requires us to remove duplicates from a sorted array in-place while maintaining the original order of elements. Since the array is sorted, duplicates are consecutive. This means we can efficiently identify and skip duplicates by comparing each element to the last unique element identified.

Approach

The key is to keep track of the position at which the next unique element should be placed. We start with an index pointing to the first position. As we iterate through the array, we compare each element with the last unique element found. If an element is greater than this last unique element, it means we have encountered a new unique number. We then place this new unique element at the current index and increment the index.

Initialize a variable currentNumber to store the last added unique number. Set it to a value less than the smallest possible element (e.g., int.MinValue).
Use an index variable to track the position to insert the next unique number. Start with 0.
Iterate over each element in nums.
- If the current element num is greater than currentNumber, it is a unique number not yet added.
- Update currentNumber with num and place num at the current index.
- Increment index to prepare for the next possible unique number.
After processing, index will be the count of unique numbers, and the first index elements in nums will be the unique elements.

Complexity

Time complexity: The algorithm iterates through the array once, making the time complexity (O(n)) where (n) is the length of the array.
Space complexity: The algorithm uses a constant amount of extra space, so the space complexity is (O(1)).

Code

public class Solution {
    public int RemoveDuplicates(int[] nums) {
        var currentNumber = int.MinValue;
        var index = 0;

        foreach(var num in nums){
            if(num > currentNumber)
            {
                currentNumber = num;
                nums[index++] = currentNumber;
            }
        }

        return index;
    }
}

Video

Conclusion

With this approach, we efficiently remove duplicates in-place resulting in the desired number of unique elements at the beginning of the array without using any additional space beyond a few variables.

References

Remove Duplicates from Sorted Array - LeetCode

1. Two Sum | LeetCode in C# | Hash Table Solution

junian — Fri, 08 Nov 2024 11:51:32 +0000

Intuition

Upon revisiting the Two Sum problem, my initial thought was that while a brute force method can solve it, there should be a more efficient way to leverage the data itself to keep track of needed values. A hash table seemed promising, as it could allow for quick look-ups to find whether the complement needed to reach the target sum has been encountered before.

Approach

The approach involves using a dictionary to store each number in the array as a key, and its index as the value. As we iterate through the array, for each number 'a', we calculate its complement 'b' such that b = target - a. We then check if 'b' already exists in the dictionary. If it does, it means we have found the two numbers that make up the target sum, and we can return their indices. If 'b' is not found, we add 'a' to the dictionary with its index. This way, we only traverse the list once, making it much more efficient than the brute force approach.

Complexity

Time complexity: The time complexity is O(n), where 'n' is the number of elements in the input array, since we make a single pass over the array and look up operations have constant time complexity.
Space complexity: The space complexity is also O(n)because, in the worst case, we might store all the numbers in the dictionary.

Code

public class Solution {
    public int[] TwoSum(int[] nums, int target) {
        var dict = new Dictionary<int, int>();

        for(var i=0; i<nums.Length; i++) {
            var a = nums[i];
            var b = target - a;

            if(dict.ContainsKey(b))
                return new int[]{dict[b], i};

            if(!dict.ContainsKey(a))
                dict.Add(a, i);
        }

        return new int[]{0,1};
    }
}

Video

Conclusion

This approach efficiently solves the problem by reducing the number of operations needed to find the solution, making it suitable for larger datasets compared to the brute force method. Using a dictionary allows for fast look-up times to check the presence of complements, thereby optimizing the solution.

References

Two Sum - LeetCode

Removing Full-Screen Intent Permission from Flutter Android

junian — Sat, 12 Oct 2024 06:13:36 +0000

This article was originally published at Junian Dev Blog

Today I'm trying to submit a new version of the Flutter Android app to Google Play Store.
I didn't put any new features, just some bug fixes.
I didn't even change the dependencies.
Normally no issue whatsoever when I send it to the Google Play Store.

But, something unexpected happened.
I got an error message from the Play Store with the following message.

Your app uses the USE_FULL_SCREEN_INTENT permission. From May 31, 2024, some apps may no longer be eligible to have this permission pre-granted at install. Apps that aren't eligible or approved for this, must request permission from the user to launch an activity with full-screen intent. If the permission isn't granted and you don't check for this, your app will crash when full-screen intent is being used.

Well, this is unusual.

I didn't use that permission in my app.
So it's probably coming from one of my dependencies.

Luckily, it's an easy fix.

To fix this issue, we just need to add a few lines to the AndroidManifest.xml file.

You can find the manifest file at android/app/src/main/AndroidManifest.xml.
Here's what the content of my manifest file looks like before I fix the issue.

<manifest xmlns:android="http://schemas.android.com/apk/res/android">
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.INTERNET"/>

    <application>
        <!-- ... -->
    </application>
</manifest>

Now let's fix it by adding some configuration lines.

The first one is to add following snippet to manifest tag.

xmlns:tools="http://schemas.android.com/tools"

Then you also need to add the following user permission removal under the manifest tag.

<uses-permission
    android:name="android.permission.USE_FULL_SCREEN_INTENT"
    tools:node="remove" />

The final AndroidManifest.xml file will look something like the following snippet.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          xmlns:tools="http://schemas.android.com/tools">
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission
        android:name="android.permission.USE_FULL_SCREEN_INTENT"
        tools:node="remove" />

    <application>
        <!-- ... -->
    </application>
</manifest>

Once you make the changes, update your app version, and republish to Google Play Store.
This time it won't have any issue!

Thanks for reading and have a good day!