Foundations -> C++ Language¶

Core C++ contest toolkit: fast I/O, references and value semantics, STL primitives, and the subset of the language that matters most under time pressure.

Topic slug: foundations/cpp-language
Tutorial page: Open tutorial
Ladder page: Open ladder
Repo problems currently tagged here: 3
Repo companion pages: 3
Curated external problems: 6

Microtopics¶

fast-io
value-vs-reference
const-correctness
vector-and-pair
sort-and-lower_bound
maps-and-sets
priority_queue
overflow-discipline

Learning Sources¶

Source	Type
cppreference language	`Primary`
cppreference containers	`Primary`
cppreference algorithms	`Primary`

Practice Sources¶

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

Repo Companion Material¶

Material	Type
Foundations cheatsheet	`quick reference`
Templates overview	`template guide`
STL basics ladder	`adjacent ladder`

Curated External Problems¶

Warm-Up¶

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
Missing Number	`CSES`	`Easy`	-	Implementation-Heavy	Basic Arithmetic; Arrays; Input/Output	Arrays; Math; Accumulation; Scan	Good practice for reading values, tracking a simple invariant, and avoiding off-by-one mistakes.
Repetitions	`CSES`	`Easy`	-	Implementation-Heavy	Strings; Loops; Basic Comparisons	Scanning; Runs; Run-Length; Scan	Reinforces careful string scanning and run-length style logic without extra data structures.
Weird Algorithm	`CSES`	`Easy`	-	Implementation-Heavy	Basic Loops; Branching; Input/Output	Simulation; Loops; I/O; Branching	A clean first task for writing a loop, handling parity, and printing a sequence correctly.

Core¶

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
Coin Piles	`CSES`	`Easy`	-	-	-	Parity; Cases; Math	Great first problem for branch logic and case analysis.
Permutations	`CSES`	`Easy`	-	Implementation-Heavy	Loops; Arrays; Simple Constructive Ideas	Construction; Parity; Output-Formatting	A nice starter for constructing outputs with a simple parity-based pattern.

Theory / Course¶

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
Increasing Array	`CSES`	`Easy`	-	Proof-Heavy; Implementation-Heavy	Arrays; Greedy Reasoning; Prefix Invariants	Arrays; Invariants	A compact proof-by-invariant problem where the implementation is simple but the invariant matters.

Repo Problems¶

Code	Title	Fit	Difficulty	Pattern	Note	Solution
`DISTINCTNUMBERS`	Distinct Numbers	`secondary`	`easy`	sort unique; container deduplication; stl algorithms	Note	Code
`MISSINGNUMBER`	Missing Number	`primary`	`easy`	running total subtraction; arithmetic series sum; type safe warm-up	Note	Code
`WEIRDALGORITHM`	Weird Algorithm	`primary`	`easy`	simulation loop; parity branching; first local workflow	Note	Code

Regeneration¶

python3 scripts/generate_problem_catalog.py