Cracking the Autodesk Technical Interview: Master LeetCode 3069 in Java

Preparing for software engineering interviews at leading technology companies requires a solid grasp of core algorithmic concepts and array manipulation techniques. If you are targeting a technical role at Autodesk, LeetCode 3069 ("Distribute Elements Into Two Arrays I") is an excellent problem to practice. It tests a candidate's ability to implement array simulation rules cleanly and efficiently under time constraints.

Understanding LeetCode 3069

The problem requires you to distribute elements from an initial integer array, nums, into two distinct arrays, arr1 and arr2, based on a simple set of deterministic rules:

1. Place the first element (nums[0]) into arr1.
2. Place the second element (nums[1]) into arr2.
3. For every remaining element nums[i] (from index 2 onwards), compare the last inserted element of arr1 with the last inserted element of arr2:
4. If the last element of arr1 is strictly greater than the last element of arr2, append nums[i] to arr1.
5. Otherwise, append nums[i] to arr2.
6. Finally, concatenate arr1 and arr2 to form the resulting array.

Step-by-Step Java Solution

To solve this problem efficiently in a technical interview setting like Autodesk, you can use standard dynamic lists (ArrayList<Integer>) to append elements dynamically without needing to pre-allocate exact array sizes upfront.

Here is the straightforward breakdown of the logic:

• Initialization: Create two lists, arr1 and arr2. Instantly add nums[0] to arr1 and nums[1] to arr2.
• Iterative Logic: Loop through the original array starting at index 2.
• Comparison: Inspect arr1.get(arr1.size() - 1) against arr2.get(arr2.size() - 1). Use a simple conditional statement to push nums[i] into the appropriate list.
• Result Construction: Create a final primitive integer array of size nums.length, copy all elements from arr1, and then append all elements from arr2.

Complexity Analysis

• Time Complexity: $O(n)$, where $n$ is the length of nums. We traverse the array exactly once, making the time complexity linear and optimal.
• Space Complexity: $O(n)$, required to store elements across the two dynamic arrays and output result.

Final Thoughts

Mastering foundational simulation problems like LeetCode 3069 boosts both your speed and code fluency. Demonstrating clean, bug-free implementation on straightforward array tasks helps build strong momentum during your Autodesk software engineering interview process.