Data update

Task/Dijkstras-algorithm/Tcl/dijkstras-algorithm-2.tcl

@@ -1,16 +1,34 @@
-proc makeUndirectedGraph arcs {
+proc makeDirectedGraph arcs {
     # Assume that all nodes are connected to something
     foreach arc $arcs {
 	lassign $arc v1 v2 cost
 	dict set graph $v1 $v2 $cost
-	dict set graph $v2 $v1 $cost
+    # dict set graph $v2 $v1 $cost ; # make undirected by adding reverse weight
     }
     return $graph
 }
+
+#                      a----7---b
+#                     / \      / \
+#                    /   9   10  15
+#                   /     \  /     \
+#                  14      c---11---d---6---e
+#                 /       /                /
+#                /       2                9
+#               f-------/----------------/
+#
+#
+
+# directed edges
 set arcs {
-    {a b 7} {a c 9} {b c 10} {b d 15} {c d 11}
-    {d e 6} {a f 14} {c f 2} {e f 9}
+    {a b 7} {a c 9} {a f 14}
+    {b c 10} {b d 15}
+    {c d 11} {c f 2}
+    {d e 6}
+    {e f 9}
 }
-lassign [dijkstra [makeUndirectedGraph $arcs] "a"] costs path
+
+# processing starts here
+lassign [dijkstra [makeDirectedGraph $arcs] "a"] costs path
 puts "path from a to e costs [dict get $costs e]"
 puts "route from a to e is: [join [dict get $path e] { -> }]"