usaco-guide/README.md

Stuff

• USACO -> CPH Topics
• Riya's website
• IOI Syllabus
• Darren's book
• Division-Specific Categorization
• Silver Categorization

Italics = mostly appears in higher divisions but still good to learn

Intro

• Assumed Prerequisites
  • first half of AP Computer Science A
  • for loops, ifs
• Containers
  • Arrays (C++11)
  • Vector / ArrayList
  • C++ pairs
  • Structs?
• What is Competitive Programming?
  • how to practice, debug
  • good practices for contests
  • contest format
• Introduction to Contests
  • format
  • plenty of examples involving file I/O
  • submitting, verdicts
• Introductory Problems
  • Be explicit about how to implement things (say "arrays" or "for-loops" probably??)
  • ex. Fence Painting
  • ex. Word Processing

Bronze

• Rectangle Geometry :o
  • see book ch 7
  • ex. Billboard
  • usually just loop over 2D array
• Simulation
  • do what statement tells you to do
  • ex. The Lost Cow
• Brute Force (Complete Search)
  • CPH 5.1, 5.2, 5.3
  • try all possibilities
  • ex. Tracing
  • iterating through permutations
    • next_permutation
    • generating recursively
  • subsets with bitwise operations??
    • not sure when this is applicable
• "Observation"
  • actually have to think a bit :D
  • ex. Mad Scientist
  • usually considered to be silver?

Silver

• Greedy
  • CPH 6
• Containers from C++ standard template library (STL)
  • CPH 4
  • Linear
    • Queues / Deques
    • C++ Lists?
    • Linked List
    • Stacks
  • Log
    • Priority Queues
    • BST / TreeSet / TreeMap (Python doesn’t have log n map)
    • Sets / Maps
    • Multiset (F FOR JAVA) (just teach a workaround or smthn ig) TreeMap<value,numoccrances> (erase by value pitfall)
    • Custom comparator (prerequisite for basically all silver topics in Java)
  • HashSets / HashMaps
• Sorting, Binary Search (BinSearch)
  • CPH 3
  • std::sort / Collections.sort
  • coord compress
  • ex. Counting Haybales
• Two Pointers (2P)
  • CPH 8.1
  • ex. Diamond Collector
• Prefix Sums (Psum)
  • CPH 9.1
  • aka Cumulative Sum, Partial Sums
  • ex. Breed Counting
  • 2D
• Graphs
  • CSAcademy Lessons
  • CPH 11, 12
  • Terminology
    • ex. bipartite graphs??
  • Flood Fill (FF)
    • finding the number of connected components in a graph
    • frequently on grid
      • ex. Switching on the Lights
    • Depth First Search (DFS)
  • Breadth First Search (BFS)
  • Disjoint Set Union (DSU)
    • no silver question should require either of the last two, but good to know
• Permutations
  • Cycle Decomposition?
  • ex. Swapity Swapity Swap

Gold

• Dynamic Programming (DP)
  • CPH 7
  • Knapsack
  • LIS
  • on tree?
  • Bitmasks??
  • Range DP???
• Amortized Analysis?
  • CPH 8.2, 8.3
• Graphs
  • Shortest Path (SP)
    • Dijkstra
      • ex. Milk Pumping
    • Bellman-Ford
    • Floyd-Warshall
    • SPFA??
    • CPH 13
  • Lowest Common Ancestor (LCA)
    • CPH 14, 18?
    • hasn’t been required aside from cowland
      • probably won't see a repeat of this
    • Milk Visits also mentions it
      • but no binary jumping required ...
  • Minimum Spanning Tree (MST)
    • CPH 15
    • ex. Fencedin
    • Prim
    • Kruskal
  • Topological Sort (TopoSort)
    • CPH 16
    • ex. Timeline
• 1D Range Queries (1DRQ)
  • mostly point update and sum query
  • ex. Haircut
• Number Theory
  • Prime factorization, GCD, LCM
  • Modular Arithmetic
  • Fast Exponentiation
  • ex. Cow Poetry
• Other
  • Bitset??
  • Combinatorics
    • Principle of Inclusion and Exclusion (PIE) once?
    • ex. Cowpatibility
  • Geometry
    • Cross product, dot product, geometry primitives (shoelace, etc.)
    • Sweepline
    • CPH 29, 30.1?
  • Strings
    • CPH 26.1, 26.2, 26.3
    • Hashing (once)?
      • Cownomics
    • Trie?