I would like to know if it is possible in Tikz graphs put the weight above the vertice (this way, all edges to the destination node has the same weight) instead above the edge. Here is an example:
A simple solution is to place the weight at the north of your node, using the above style option :
which gives the result:
There's a simple way to tag on a node relative to the position of another node. To do that for the top left corner of your graph, take a look at the following code:
The result will be this:
Here is a bit more automated way to do so (in order to avoid the deferred definition of labels). The bases are taken from Modify nodes in TikZ? and the beauty of this approach is that one can decide to position the label or not immediately when the node is defined. Also some customization of the aspect are possible.
The example (structure stolen from JimboBimbo):
The first argument of
Notice that the previous approach is not the only possible. In a simpler manner:
will lead to the same picture reported above.