Initial data commit

Task/Floyd-Warshall-algorithm/FreeBASIC/floyd-warshall-algorithm.basic

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+' FB 1.05.0 Win64
+
+Const POSITIVE_INFINITY As Double = 1.0/0.0
+
+Sub printResult(dist(any, any) As Double, nxt(any, any) As Integer)
+  Dim As Integer u, v
+  Print("pair     dist    path")
+  For i As Integer = 0 To UBound(nxt, 1)
+    For j As Integer = 0 To UBound(nxt, 1)
+      If i <> j Then
+        u = i + 1
+        v = j + 1
+        Print Str(u); " -> "; Str(v); "    "; dist(i, j); "     "; Str(u);
+        Do
+          u = nxt(u - 1, v - 1)
+          Print " -> "; Str(u);
+        Loop While u <> v
+        Print
+      End If
+    Next j
+  Next i
+End Sub
+
+Sub floydWarshall(weights(Any, Any) As Integer, numVertices As Integer)
+  Dim dist(0 To numVertices - 1, 0 To numVertices - 1) As Double
+  For i As Integer = 0 To numVertices - 1
+    For j As Integer = 0 To numVertices - 1
+      dist(i, j) = POSITIVE_INFINITY
+    Next j
+  Next i
+
+  For x As Integer = 0 To UBound(weights, 1)
+    dist(weights(x, 0) - 1, weights(x, 1) - 1) = weights(x, 2)
+  Next x
+
+  Dim nxt(0 To numVertices - 1, 0 To numVertices - 1) As Integer
+  For i As Integer = 0 To numVertices - 1
+    For j As Integer = 0 To numVertices - 1
+      If i <> j Then nxt(i, j) = j + 1
+    Next j
+  Next i
+
+  For k As Integer = 0 To numVertices - 1
+    For i As Integer = 0 To numVertices - 1
+      For j As Integer = 0 To numVertices - 1
+        If (dist(i, k) + dist(k, j)) < dist(i, j) Then
+          dist(i, j) = dist(i, k) + dist(k, j)
+          nxt(i, j) = nxt(i, k)
+        End If
+      Next j
+    Next i
+  Next k
+
+  printResult(dist(), nxt())
+End Sub
+
+Dim weights(4, 2) As Integer = {{1, 3, -2}, {2, 1, 4}, {2, 3, 3}, {3, 4, 2}, {4, 2, -1}}
+Dim numVertices As Integer = 4
+floydWarshall(weights(), numVertices)
+Print
+Print "Press any key to quit"
+Sleep