Chtholly¶

Ordered-set interval partition for piecewise-constant arrays where range assign keeps collapsing runs and range walks are acceptable.

Microtopics¶

Source	Type
OI Wiki ODT	`Reference`
Codeforces Round #449 Editorial	`Reference`
CF896C Willem, Chtholly and Seniorious	`Practice`

Source	Type
CF915E Physical Education Lessons	`Practice`

Material	Type
ODT / Chtholly hot sheet	`quick reference`
Willem, Chtholly and Seniorious	`flagship note`
Lazy Segment Tree tutorial	`compare point`
Template Library exact starter route	`starter route`

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
896C - Willem, Chtholly and Seniorious	`Codeforces`	`Hard`	Interval-Partition	Data-Structure-Heavy; Implementation; Randomized-Input	Ordered Set Iteration; Split(l) / Split(r + 1); Range Assign	Range Assign; Ordered Set; Expected Complexity; Kth Query	The canonical Chtholly-tree benchmark where split, assign, and interval walks over the current runs are the whole model.

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
915E - Physical Education Lessons	`Codeforces`	`Hard`	Interval-Partition	Data-Structure-Heavy; Query-Heavy	Ordered Set Iteration; Range Assign; Current Interval Partition	Range Assign; Piecewise Constant; Interval Counting	A clean deterministic bridge where interval assign and counting over the current partition are the real invariants even without the full CF896C random-data flavor.

Code	Title	Fit	Difficulty	Pattern	Note	Solution
`WILLEMCHTHOLLYANDSENIORIOUS`	Willem, Chtholly and Seniorious	`primary`	`hard`	-	Note	Code

python3 scripts/generate_problem_catalog.py