Gold
The topics below are not exhaustive for this division.
Contest problems may contain topics not covered in the guide, or topics listed under different divisions!
Modules Progress
Problems Progress
Math
Dynamic Programming
Most Gold and Platinum contests have at least one DP problem.
Introduction to DP
Very Frequent
Speeding up naive recursive solutions with memoization.
Updated: 22 hours ago
Knapsack DP
Rare
Problems that can be modeled as filling a limited-size container with items.
Updated: 22 hours ago
Paths on Grids
Not Frequent
Counting the number of "special" paths on a grid, and how some string problems can be solved using grids.
Updated: 43 minutes ago
Longest Increasing Subsequence
Has Not Appeared
Finding and using the longest increasing subsequence of an array.
Updated: Yesterday
Bitmask DP
Not Frequent
DP problems that require iterating over subsets.
Updated: 2 days ago
Range DP
Rare
Solving a DP problem on every contiguous subarray of the original array.
Updated: 2 days ago
Digit DP
Rare
Finding the number of integers in a range that have a property.
Updated: Yesterday
Graphs
Most Silver to Platinum contests have at least one graph problem.
Shortest Paths with Unweighted Edges
Somewhat Frequent
Introduces how BFS can be used to find shortest paths in unweighted graphs.
Updated: 22 hours ago
Disjoint Set Union
Somewhat Frequent
The Disjoint Set Union (DSU) data structure, which allows you to add edges to a graph and test whether two vertices of the graph are connected.
Updated: 22 hours ago
Topological Sort
Rare
Ordering the vertices of a directed acyclic graph such that each vertex is visited before its children.
Updated: Yesterday
Shortest Paths with Non-Negative Edge Weights
Not Frequent
Bellman-Ford, Floyd-Warshall, and Dijkstra.
Updated: 22 hours ago
Minimum Spanning Trees
Rare
Finding a subset of the edges of a connected, undirected, edge-weighted graph that connects all the vertices to each other of minimum total weight.
Updated: Yesterday
Data Structures
More Operations on Sorted Sets
Not Frequent
Finding the next element smaller or larger than a specified key in a sorted set, and using iterators with sorted sets.
Updated: 2 days ago
(Optional) Sorted Sets with Custom Comparators
Rare
Incorporating custom comparators into standard library containers.
Updated: 5 months ago
Stacks
Not Frequent
A data structure that only allows insertion and deletion at one end.
Updated: Yesterday
Sliding Window
Somewhat Frequent
Maintaining data over consecutive subarrays.
Updated: 22 hours ago
Point Update Range Sum
Somewhat Frequent
Segment Tree, Binary Indexed Tree, and Order Statistic Tree (in C++).
Updated: 22 hours ago
Trees
DP on Trees - Introduction
Not Frequent
Using subtrees as subproblems.
Updated: 2 days ago
DP on Trees - Solving For All Roots
Rare
Tree DP problems involving rerooting.
Updated: 22 hours ago
(Optional) Euler Tour Technique
Rare
Flattening a tree into an array to easily query and update subtrees.
Updated: Yesterday
(Optional) LCA with Euler Tour
Rare
Finding the lowest common ancestor by reducing it to a range minimum query over an Euler tour.
Updated: 2 days ago
Additional Topics
Rarely required.
Optimizing Unimodal Functions
Rare
Using ternary or binary search to find the mode of unimodal functions.
Updated: 2 days ago
Hashing
Rare
Quickly testing equality of substrings or sets with a small probability of failure.
Updated: 2 days ago
(Optional) Hashmaps
Rare
Maintaining collections of distinct elements with hashing.
Updated: 22 hours ago
(Optional) Meet In The Middle
Rare
Problems involving dividing the search space into two.
Updated: Yesterday
Conclusion
Congratulations on making it this far!