Robinhood

Online Assessment
Online Assessment//Number of Orders in the Backlog
Q2
Medium50 Marks

Number of Orders in the Backlog

ArrayHeap (Priority Queue)Simulation
Set 1 • 90 min
Problem Statement

In Robinhood's technical coding assessment, candidates are evaluated on clean algorithmic problem-solving for "Number of Orders in the Backlog".

Given standard input parameters adhering to Array principles, design an optimal algorithm that satisfies all constraints and handles boundary test scenarios efficiently.

Ensure your implementation minimizes memory overhead and executes within the allotted online assessment time limits.

Candidate Instructions
  • ▸Identify the core invariant related to Array.
  • ▸Verify edge cases including empty inputs and extreme bounds.
  • ▸Optimize time complexity before submitting.
Input Format
  • ▸The first line specifies the dimensions or count of test elements N.
  • ▸The subsequent line(s) contain the input array, string, or graph representation.
Output Format
  • ▸Print the computed result adhering to the required return format.
Constraints
  • 1 <= N <= 10^5
  • -10^9 <= element[i] <= 10^9
  • Time Limit: 2.0 seconds
  • Memory Limit: 256 MB
Edge Cases
  • ▸Empty or single-element input
  • ▸Input containing maximum or minimum boundary values
  • ▸Uniform elements or all-negative test cases
Sample Test Cases
Example 1
Input
nums = [1, 2, 3, 4, 5], k = 3
Output
3
Explanation

Applying the optimal Array approach yields the expected solution 3.

Complexity
TimeO(N log N)
SpaceO(N)
Expected Approach

Leverage Array combined with Heap (Priority Queue), Simulation to process the input in optimal O(N log N) time complexity.