Groups
Category
Level
Bellman–Ford finds single-source shortest paths even when some edge weights are negative.
Dijkstra’s algorithm can be adapted to track the second shortest path by keeping the best and second-best distances per vertex.
Topological sort orders vertices of a directed acyclic graph (DAG) so every edge goes from earlier to later, which is perfect for dynamic programming (DP).
Breadth-First Search (BFS) explores a graph level by level, visiting all vertices at distance d from the source before any at distance d+1.
Depth-First Search (DFS) assigns each vertex a discovery time and a finish time that capture a neat nesting structure of recursion.
Topological sort orders the nodes of a directed acyclic graph (DAG) so every edge points from left to right in the order.
Multi-source BFS explores an unweighted graph starting from several sources at once to compute the minimum distance to any source for every vertex.
0-1 BFS is a shortest path algorithm specialized for graphs whose edge weights are only 0 or 1.
Depth-First Search (DFS) explores a graph by going as deep as possible along each path before backtracking.
A 2D prefix sum (also called an integral image) lets you compute the sum of any axis-aligned sub-rectangle in constant time after O(nm) preprocessing.
Prefix sums precompute running totals so any range sum [l, r] can be answered in O(1) time as prefix[r] - prefix[l-1].
Coordinate compression replaces large, sparse, or arbitrary values with small consecutive integers while preserving relative order.