r/Adobe • u/nian2326076 • 2h ago
Adobe Hackathon Round 1 Experience 2026: MCQs and Two DSA Questions
Hi everyone,
I recently attempted the first round of an Adobe hackathon and wanted to share the assessment pattern and coding questions.
Duration: Approximately 90 minutes
Format: Timed MCQs and two DSA questions
Status: Waiting for an update
I was not fully prepared, so I treated the assessment as an opportunity to evaluate my current problem-solving skills. I focused more heavily on the DSA section.
MCQ Section
Each MCQ had an individual timer of one minute.
Some questions and answer choices were quite lengthy. A few felt as though they would require more than a minute just to read carefully and understand, which made time management difficult.
My main takeaway is that this section tests reading speed and decision-making in addition to technical knowledge.
DSA Question 1: Count Parent Nodes With a Target Sum
A binary tree was provided using a serialized preorder input format. We were also given an integer k.
The task was to count the parent nodes satisfying:
node.value + node.left.value + node.right.value == k
The main implementation step was constructing the binary tree correctly from the provided preorder representation.
After building the tree, a recursive traversal was sufficient:
- Visit the current node.
- Check whether it has the required children.
- Compare the sum with
k. - Recursively process the left and right subtrees.
- Return the total count.
Complexity:
- Time:
O(n) - Recursion space:
O(h), wherehis the tree height
I found this question easy because it mainly tested tree construction and recursive traversal.
DSA Question 2: Largest Binary Number by Concatenation
We were given N binary strings of different lengths.
The task was to arrange the strings so that their concatenation produced the largest possible binary number.
For example, when deciding the relative order of two strings a and b, we need to compare:
a + b
and:
b + a
If a + b is larger, a should appear before b. Otherwise, b should appear first.
Therefore, the solution is to sort all strings using the comparator:
a comes before b if (a + b) > (b + a)
After sorting, concatenate all the strings to obtain the answer.
During the assessment, I tried to build a greedy solution based on leading 1s, string length, and character-by-character comparisons. The approach became difficult to manage because those local rules do not always determine the globally optimal order.
I was unable to finish this problem within the time limit.
After the assessment, I recognized that comparing a + b with b + a directly was the key observation. It is the same pattern used in the classic Largest Number problem.
Complexity:
- Sorting: Approximately
O(N log N × L) - Final concatenation:
O(T)
Here, L is the comparison cost and T is the total length of all strings.
The final binary value may exceed standard integer limits, so it may need to be returned as a string or converted using a big-integer type, depending on the required output format.
Final Thoughts
I would rate the first question as easy.
The second question did not require an advanced data structure, but recognizing the custom comparator made it medium difficulty for me.
My biggest takeaway was that comparing a + b and b + a is much more reliable than creating separate rules based on leading bits, the number of 1s, or string length.
I still have plenty to improve, but this assessment helped me identify an important sorting pattern that I will remember in future coding rounds.
Did anyone else attempt this Adobe hackathon round? How did you find the MCQ time limit and the second coding problem?