Dijkstra’s shortest path algorithm
Properties
•It
computes the minimum cost path from the seed to every node
in the graph. This set of minimum paths
is represented as a tree
•Running
time, with N pixels:
–O(N2)
time if you use an active list
–O(N
log N) if you use an active priority queue (heap)
–takes
fraction of a second for a typical (640x480) image
•Once
this tree is computed once, we can extract the optimal path
from any point to the seed in O(N) time.
–it
runs in real time as the mouse moves
•What
happens when the user specifies a new seed?