FilesExpand file tree

master

/

DijkstraSmallestPath.js

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

110 lines (95 loc) · 2.33 KB

master

/

DijkstraSmallestPath.js

Copy path

Top

File metadata and controls

• Code
• Blame

110 lines (95 loc) · 2.33 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

// starting at s

function solve (graph, s) {

const solutions = {}

solutions[s] = []

solutions[s].dist = 0

while (true) {

let p = null

let neighbor = null

let dist = Infinity

for (const n in solutions) {

if (!solutions[n]) { continue }

const ndist = solutions[n].dist

const adj = graph[n]

for (const a in adj) {

if (solutions[a]) { continue }

const d = adj[a] + ndist

if (d < dist) {

p = solutions[n]

neighbor = a

dist = d

}

}

}

// no more solutions

if (dist === Infinity) {

break

}

// extend parent's solution path

solutions[neighbor] = p.concat(neighbor)

// extend parent's cost

solutions[neighbor].dist = dist

}

return solutions

}

export { solve }

// // create graph

// const graph = {}

// const layout = {

// R: ['2'],

// 2: ['3', '4'],

// 3: ['4', '6', '13'],

// 4: ['5', '8'],

// 5: ['7', '11'],

// 6: ['13', '15'],

// 7: ['10'],

// 8: ['11', '13'],

// 9: ['14'],

// 10: [],

// 11: ['12'],

// 12: [],

// 13: ['14'],

// 14: [],

// 15: []

// }

// // convert uni-directional to bi-directional graph

// let graph = {

// a: {e:1, b:1, g:3},

// b: {a:1, c:1},

// c: {b:1, d:1},

// d: {c:1, e:1},

// e: {d:1, a:1},

// f: {g:1, h:1},

// g: {a:3, f:1},

// h: {f:1}

// };

// for (const id in layout) {

// if (!graph[id]) { graph[id] = {} }

// layout[id].forEach(function (aid) {

// graph[id][aid] = 1

// if (!graph[aid]) { graph[aid] = {} }

// graph[aid][id] = 1

// })

// }

// // choose start node

// const start = '10'

// // get all solutions

// const solutions = solve(graph, start)

// // for s in solutions..

// ' -> ' + s + ': [' + solutions[s].join(', ') + '] (dist:' + solutions[s].dist + ')'

// From '10' to

// -> 2: [7, 5, 4, 2] (dist:4)

// -> 3: [7, 5, 4, 3] (dist:4)

// -> 4: [7, 5, 4] (dist:3)

// -> 5: [7, 5] (dist:2)

// -> 6: [7, 5, 4, 3, 6] (dist:5)

// -> 7: [7] (dist:1)

// -> 8: [7, 5, 4, 8] (dist:4)

// -> 9: [7, 5, 4, 3, 13, 14, 9] (dist:7)

// -> 10: [] (dist:0)

// -> 11: [7, 5, 11] (dist:3)

// -> 12: [7, 5, 11, 12] (dist:4)

// -> 13: [7, 5, 4, 3, 13] (dist:5)

// -> 14: [7, 5, 4, 3, 13, 14] (dist:6)

// -> 15: [7, 5, 4, 3, 6, 15] (dist:6)

// -> R: [7, 5, 4, 2, R] (dist:5)