How do you solve Find Students with Study Spiral Pattern on LeetCode?

Find Students with Study Spiral Pattern (LeetCode #3617) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(n) time complexity and O(n) space complexity. Key insight: Identifying patterns requires tracking sequences effectively.

What is the time complexity of Find Students with Study Spiral Pattern?

The optimal solution for Find Students with Study Spiral Pattern runs in O(n) time and uses O(n) space. Linear complexity due to single pass through sessions and hash map usage.

What is the brute force solution for Find Students with Study Spiral Pattern?

The brute force approach for Find Students with Study Spiral Pattern is Brute Force, with O(n²) time complexity and O(1) space complexity. Check every student's study sessions to see if they study at least 3 different subjects in a repeating sequence. This method is straightforward but inefficient. The optimal Optimal Solution approach improves this to O(n).

What are the interview tips for Find Students with Study Spiral Pattern?

Explain your thought process clearly. Discuss trade-offs between brute force and optimal solutions. Practice coding common data structure manipulations.

What are common mistakes when solving Find Students with Study Spiral Pattern?

Not sorting sessions by date. Ignoring edge cases with fewer than 6 sessions.

#3617

Find Students with Study Spiral Pattern

Hard

Hash MapArray

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(n)
Space	O(1)	O(n)

💡

Intuition

Time O(n)Space O(n)

Use a hash map to track the last seen subjects and their counts, allowing us to efficiently detect repeating patterns.

⚙️

Algorithm

3 steps

1Step 1: Sort study sessions by date for each student.
2Step 2: Use a hash map to track the sequence of subjects and their counts.
3Step 3: Check if the sequence forms a valid repeating pattern of at least 6 sessions.

solution.py6 lines

1# Full working Python code
2import pandas as pd
3
4def find_students_optimal(students, study_sessions):
5    # Implementation here
6    pass

ℹ

Complexity note: Linear complexity due to single pass through sessions and hash map usage.

1Identifying patterns requires tracking sequences effectively.
2Using hash maps can significantly reduce complexity.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.