Foundations -> Sorting¶

Sorting as a modeling tool: order data to expose monotonicity, simplify sweeps, or make greedy decisions provable.

Microtopics¶

Source	Type
OI Wiki sorting intro	`Reference`
cppreference std::sort	`Primary`
Competitive Programmer's Handbook	`Reference`

Source	Type
CSES Problem Set	`Practice`
Codeforces sortings tag	`Practice`

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
Apartments	`CSES`	`Easy`	-	Greedy-Heavy; Implementation-Heavy	Sorting; Two Pointers; Greedy Matching	Two-Pointers; Matching; Sort	A classic sorted two-pointer matching problem with a very clean greedy proof.
Movie Festival	`CSES`	`Easy`	-	Greedy-Heavy	Sorting; Interval Scheduling; Greedy	Intervals; Sort	A textbook interval-scheduling problem that rewards sorting by finish time.
Reading Books	`CSES`	`Easy`	-	Greedy-Heavy	Sorting; Greedy Scheduling; Prefix Sums	Scheduling	A nice example of sorting plus a simple optimization argument.
Tasks and Deadlines	`CSES`	`Medium`	-	-	-	Sort; Ordering	A very standard sort-by-duration optimization.

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
Ferris Wheel	`CSES`	`Easy`	-	Greedy-Heavy	Sorting; Pairing; Two Pointers	Two-Pointers; Pairing; Sort	One of the most recognizable introductory sorting-and-greedy pairings.
Stick Lengths	`CSES`	`Medium`	-	Math-Heavy; Greedy-Heavy	Sorting; Median; Absolute Deviations	Median; Absolute-Deviation	A classic benchmark for the median-minimizes-L1-cost idea after sorting.

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
Nested Ranges Check	`CSES`	`Medium`	-	Proof-Heavy; Greedy-Heavy	Sorting; Interval Containment; Sweep-Line Ideas	Intervals; Containment	A strong sorting problem where handling interval order and ties is the main challenge.

Code	Title	Fit	Difficulty	Pattern	Note	Solution
`APARTMENTS`	Apartments	`secondary`	`easy-medium`	two sorted pointers; tolerance matching; greedy monotone scan	Note	Code
`FERRISWHEEL`	Ferris Wheel	`primary`	`easy-medium`	opposite end pointers; greedy pairing; sorted capacity matching	Note	Code
`LEMONADELINE`	Lemonade Line	`secondary`	`easy`	descending tolerance order; prefix feasibility count; minimize accepted arrivals	Note	Code
`MOVIEFESTIVAL`	Movie Festival	`primary`	`easy`	finish-time sorting; interval scheduling; exchange argument greedy	Note	Code
`SUMOFTWOVALUES`	Sum of Two Values	`secondary`	`medium`	sort and scan; opposite end pointers; index restoration	Note	Code

python3 scripts/generate_problem_catalog.py