The following is a tabular presentation of the Dijkstra SSAD algorithm trace 
from the Weighted Graph notes; x denotes infinity.


  a    b    c    d    e    f    g    h    i    Node added / distance
----------------------------------------------------------------------------
  0   
add   15   25    x    x    x    x    x    x        a   0
     add   25    x   25    x    x   20   40        b  15
           25    x   25    x    x  add   35        h  20
          add   35   25    x    x        35        c  25
                35  add   35   30        35        e  25
                35        35  add        35        g  30
               add        35             35        d  35
                         add             35        f  35
                                        add        i  35
----------------------------------------------------------------------------