Dijkstra
Detailed guide and Python implementation for the 'Dijkstra' problem.
Problem Statement
Write a function dijkstra(graph, start) that calculates the shortest path from a starting node start to all other nodes in a weighted graph. The graph is represented as an adjacency list of dictionaries, where graph[u][v] is the weight of the directed edge from u to v. Return a dictionary of shortest distances.
- •1 <= V <= 1000
- •0 <= E <= 5000
- •Weights are non-negative integers.
Examples
graph = {0: {1: 4, 2: 1}, 1: {3: 1}, 2: {1: 2, 3: 5}, 3: {}}, start = 0{0: 0, 1: 3, 2: 1, 3: 4}Shortest distance from 0 to 1 is 3 (via 0->2->1).
Need a Hint?
Edge Cases to Watch
- Empty input structures
- Single element inputs
- Large numerical bounds
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