Algorithm dossier

  • Category: Shortest path
  • Worst-case complexity: O(n³)
  • Approach: DP
  • Data structure: Graph
  • First formalised: 1950s

Why this snippet is Bellman-Ford

Why Bellman-Ford. Single-source shortest path that *tolerates negative edge weights*. Repeats n - 1 full edge-relaxation passes — that's enough to propagate any optimal path (the longest simple path has at most n - 1 edges). Distinguisher. Dijkstra picks one vertex per pass via priority; Bellman-Ford touches *every edge every pass*. The flat for _ in 0..n-1 outer loop is the give-away.

How to read a redacted algorithm

Algodle strips identifier names so the snippet has to be read for its shape: the control flow, the data structures it manipulates, the order in which it visits its input. Loops with two pointers crawling toward each other are usually search or partition. A recursion that splits its input in half and recurses on both halves is divide-and-conquer. A priority queue plus graph traversal is almost certainly Dijkstra, Prim, or A*. Six hint columns — category, complexity, approach, data structure, era — let you triangulate even when the snippet itself is opaque.