Finds the node in bst whose data is less than that of any other
node. Note that this selection is performed without comparing nodes.
Returns a null pointer if bst is empty.
Finds the node in bst whose data is greater than that of any other
node. Note that this selection is performed without comparing nodes.
Returns a null pointer if bst is empty.
Finds the node in bst whose data compares equal to target,
or return a null pointer if no such node can be found. cmp_args
is passed as the last argument to bst's comparison function.