depth-first search
<algorithm> A graph search {algorithm} which extends the
current path as far as possible before {backtracking} to the
last {choice point} and trying the next alternative path.
Depth-first search may fail to find a solution if it enters a
cycle in the graph. This can be avoided if we never extend a
path to a node which it already contains.
Opposite of {breadth first search}. See also {iterative
deepening}.
(1995-04-19)