I applied for JP’s 26 Summer Intern at the end of last month, and received my OA not long after my resume was approved. The overall pace is quite fast, the platform is HackerRank, there are two coding steps, and the time is not tight. I finished writing this in about 20 minutes + passed the self-assessment. The overall difficulty is more basic, more clear in thinking, and not too stuck on implementation details. Let’s briefly review JPMorgan Chase 2026 Summer Intern OA question types and ideas will provide a reference for students who want to do it later.
Question 1: Interval negation operation to find the final array state
The main idea of the title is:
Given an initial array and several range operations, perform a "reverse" of the elements in the range each time. Ask for the value of each last position.
The essence of this question is not a simulation, but a difference + prefix sum.
Core idea:
- Each interval
[l, r],existLLocation +1 inR+1Position -1 - Finally, do the prefix sum to get the total number of times each position has been operated.
- If a position has been manipulated an odd number of times, it is inverted; if it is manipulated an even number of times, it remains unchanged.
The time complexity is O(n + m), which is much faster than violently flipping the interval each time.
This question is very typical. It tests whether you can use "difference array" to optimize interval operations, rather than stupidly changing it section by section.
Question 2: Maximum number of tasks running simultaneously (minimum number of machines)
The question is given the start time and end time of a bunch of tasks, and asks how many tasks are running at most at the same time, that is, how many machines are needed at least. This question is actually a classic sweep line model.
Idea:
- Each task start time is counted as +1
- The "next moment" of each task end time is recorded as -1
- Sort all time points
- Scan from small to large, accumulating the number of currently running tasks.
- The maximum value that occurs during recording
This maximum value is the answer. The essence is to transform the interval problem into "time point event statistics". The writing method is not complicated, just pay attention to the boundaries.
Learn more
If you are preparing for the 2026 Summer Intern recently, whether it is JP or other major manufacturers, you must be familiar with the common models of HackerRank / CodeSignal. The Programhelp team can write in Python/Java/C++, and the language selection mainly depends on the scenario. Want to get OA question type trends, or want to know more about Interview assistance , you can also discuss it together.
