HardGraphs
Campus Paths
Given an undirected graph of rooms and paths, count how many rooms can be reached from room 1.
Open problemProblems
Practice coding problems
Build problem-solving habits with topic filters, difficulty levels, visible examples, and an online code workspace.
Follow a guided ladder
Choose a Python Foundations, coding practice, or PCEP review path and work through problems in order.
Difficulty
Showing 5 of 30 problems
Clear filtersHardDynamic Programming
Certification Roadmap
Given module study times and readiness values, choose modules whose total time is at most `T` and maximize total readiness.
Open problemHardGreedy
Resource Schedule
Given start and end times for workshops, determine the maximum number happening at the same time. End times are exclusive.
Open problemHardPrefix Sums
Scholarship Window
Given daily practice minutes and a window size `k`, find the maximum total practice minutes over any consecutive `k` days.
Open problemHardSorting
Sorted Scores Query
Given scores and a threshold `t`, count how many scores are at least `t`.
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