Floyd-Warshall algorithm: Difference between revisions
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<pre>{a q} 6.0 {a g} 6.0 {a f} 5.0 {a e} 4.0 {a d} 3.0 {a m} 2.0 {a c} 2.0 {a p} 1.0 {a b} 1.0 {a a} 0</pre>
=={{header|Visual Basic .NET}}==
{{trans|C#}}
<lang vbnet>Module Module1
Sub PrintResult(dist As Double(,), nxt As Integer(,))
Console.WriteLine("pair dist path")
For i = 1 To nxt.GetLength(0)
For j = 1 To nxt.GetLength(1)
If i <> j Then
Dim u = i
Dim v = j
Dim path = String.Format("{0} -> {1} {2,2:G} {3}", u, v, dist(i - 1, j - 1), u)
Do
u = nxt(u - 1, v - 1)
path += String.Format(" -> {0}", u)
Loop While u <> v
Console.WriteLine(path)
End If
Next
Next
End Sub
Sub FloydWarshall(weights As Integer(,), numVerticies As Integer)
Dim dist(numVerticies - 1, numVerticies - 1) As Double
For i = 1 To numVerticies
For j = 1 To numVerticies
dist(i - 1, j - 1) = Double.PositiveInfinity
Next
Next
For i = 1 To weights.GetLength(0)
dist(weights(i - 1, 0) - 1, weights(i - 1, 1) - 1) = weights(i - 1, 2)
Next
Dim nxt(numVerticies - 1, numVerticies - 1) As Integer
For i = 1 To numVerticies
For j = 1 To numVerticies
If i <> j Then
nxt(i - 1, j - 1) = j
End If
Next
Next
For k = 1 To numVerticies
For i = 1 To numVerticies
For j = 1 To numVerticies
If dist(i - 1, k - 1) + dist(k - 1, j - 1) < dist(i - 1, j - 1) Then
dist(i - 1, j - 1) = dist(i - 1, k - 1) + dist(k - 1, j - 1)
nxt(i - 1, j - 1) = nxt(i - 1, k - 1)
End If
Next
Next
Next
PrintResult(dist, nxt)
End Sub
Sub Main()
Dim weights = {{1, 3, -2}, {2, 1, 4}, {2, 3, 3}, {3, 4, 2}, {4, 2, -1}}
Dim numVeritices = 4
FloydWarshall(weights, numVeritices)
End Sub
End Module</lang>
{{out}}
<pre>pair dist path
1 -> 2 -1 1 -> 3 -> 4 -> 2
1 -> 3 -2 1 -> 3
1 -> 4 0 1 -> 3 -> 4
2 -> 1 4 2 -> 1
2 -> 3 2 2 -> 1 -> 3
2 -> 4 4 2 -> 1 -> 3 -> 4
3 -> 1 5 3 -> 4 -> 2 -> 1
3 -> 2 1 3 -> 4 -> 2
3 -> 4 2 3 -> 4
4 -> 1 3 4 -> 2 -> 1
4 -> 2 -1 4 -> 2
4 -> 3 1 4 -> 2 -> 1 -> 3</pre>
=={{header|zkl}}==
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