Data Structures -> Heaps And Ordered Sets

Use heaps, sets, and multisets to maintain online minima/maxima, medians, and active sets.

• Topic slug: data-structures/heaps-and-ordered-sets
• Tutorial page: Open tutorial
• Ladder page: Open ladder
• Repo problems currently tagged here: 1
• Repo companion pages: 2
• Curated external problems: 7

Microtopics

• max-heap
• min-heap
• multiset
• lower_bound
• erase-one
• ordered-iteration
• median-maintenance

Learning Sources

Source	Type
cppreference priority_queue	Primary
cppreference set	Primary
USACO Guide sorted sets	Reference

Practice Sources

Source	Type
Codeforces data structures tag	Practice
CSES Problem Set	Practice

Repo Companion Material

Material	Type
Data structures cheatsheet	quick reference
Templates overview	template guide

Curated External Problems

Core

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
Restaurant Customers	CSES	Easy	-	Modeling-Heavy	Sorting; Event Sweeps; Prefix Counts	Events; Sweep Line; Maximum-Overlap	A simple and popular event-processing problem that pairs naturally with ordered scans.
Room Allocation	CSES	Medium	-	Greedy-Heavy; Data-Structure-Heavy	Priority Queues; Sorting; Interval Scheduling	Priority-Queue; Interval-Scheduling; Assignment	A classic heap-based assignment problem with a very practical greedy pattern.
Movie Festival II	CSES	Hard	-	-	-	Multiset; K-Members	A canonical multi-assign scheduling problem.

Classics

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
Concert Tickets	CSES	Medium	-	Data-Structure-Heavy; Greedy-Heavy	Ordered Sets; Greedy Matching; Lower Bound	Multiset; Predecessor-Query; Lower Bound	A classic ordered-set exercise for predecessor queries under deletions.
Traffic Lights	CSES	Medium	-	Data-Structure-Heavy	Ordered Sets; Interval Maintenance; Multisets	Ordered-Set; Intervals; Max-Gap; Neighbors	A well-known benchmark for maintaining gaps between ordered points.

Advanced

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
Sliding Window Cost	CSES	Hard	-	Data-Structure-Heavy	Median Maintenance; Multisets; Sliding Windows	Median; Absolute-Deviation	A more demanding ordered-structure problem that extends median maintenance into cost tracking.
Sliding Window Median	CSES	Hard	-	Data-Structure-Heavy	Priority Queues; Multisets; Window Maintenance	Median; Sliding-Window	A strong benchmark for maintaining order statistics with heap-like containers.

Repo Problems

Code	Title	Fit	Difficulty	Pattern	Note	Solution
CONCERTTICKETS	Concert Tickets	primary	medium	multiset predecessor; erase one occurrence; greedy ticket assignment	Note	Code

Regeneration

python3 scripts/generate_problem_catalog.py