Dijkstra

What is a Heap?

A heap is a complete binary tree stored in an array that satisfies the heap property — in a min-heap every parent is smaller than or equal to its children, giv…

What is a Priority Queue?

A priority queue is an abstract data type where each element has a priority, and the element with the highest (or lowest) priority is always removed first, typ…

What is Dijkstra’s Algorithm?

Dijkstra’s algorithm finds the shortest path from a single source vertex to every other vertex in a weighted graph with non-negative edge weights, using a gree…

What is the Bellman-Ford Algorithm?

Bellman-Ford finds shortest paths from a single source to every other vertex in a weighted graph by relaxing all edges repeatedly for V-1 rounds, and unlike Di…

What is the A* Search Algorithm?

A* search finds the shortest path between two specific nodes by combining Dijkstra's guaranteed-shortest exploration with a heuristic estimate of remaining dis…

What is a Min-Heap?

A min-heap is a complete binary tree, usually stored as an array, where every parent node is less than or equal to its children, guaranteeing the smallest elem…

What is the Single-Source Shortest Path Problem?

Single-source shortest path (SSSP) finds the minimum-cost route from one fixed source vertex to every other reachable vertex in a graph, solved with BFS for un…

What is the All-Pairs Shortest Path Problem?

All-pairs shortest path (APSP) computes the minimum-cost route between every pair of vertices in a graph at once, typically solved with the Floyd-Warshall algo…

What is Dynamic Programming on Graphs?

Dynamic programming on graphs solves problems like shortest paths, longest paths, and counting paths by defining a DP state per node (or per node-and-extra-dim…

Weighted vs Unweighted Graphs: What is the Difference?

A weighted graph attaches a numeric cost or value to each edge, such as distance or price, while an unweighted graph only records that a connection exists with…

What is OSPF (Open Shortest Path First)?

OSPF is a link-state interior gateway routing protocol that lets routers within a single autonomous system share their local link information with every other…

Distance-Vector vs Link-State Routing

Distance-vector routing (e.g., RIP) has each router share its entire routing table with only its direct neighbors and pick paths based on hop count or a simple…