# dijkstra-simple
A simpler Dijkstra shortest paths implementation
## Basic usage
This section contains basic step-by-step usage of the library.
The first step is to build a direct graph:
```
exampleGraph :: Graph Char Int
exampleGraph = Graph $ M.fromList [
('A', [EdgeTo 'B' 3, EdgeTo 'C' 1])
, ('B', [EdgeTo 'A' 3, EdgeTo 'C' 7, EdgeTo 'D' 5, EdgeTo 'E' 1])
, ('C', [EdgeTo 'A' 1, EdgeTo 'B' 7, EdgeTo 'D' 2])
, ('D', [EdgeTo 'B' 5, EdgeTo 'C' 2, EdgeTo 'E' 5])
, ('E', [EdgeTo 'B' 1, EdgeTo 'D' 7])
]
```
Then pick or create a weighter (see `Graph.DijkstraSimple.Weighters`)
and apply it all:
```
lightestPaths exampleGraph 'C' weighter
```
It will give all the reacheable vertices from `'C'` and associated shortest path:
```
Paths $ M.fromList [
('A', Path (fromList "AC") 1)
, ('B', Path (fromList "BAC") 3)
, ('C', Path (fromList "CAC") 1)
, ('D', Path (fromList "DC") 2)
, ('E', Path (fromList "EBAC") 3)
]
```