return(L); end end 5.[15] The level-order listing of the nodes of a tree first lists the root, then all nodes of depth a, then all nodes of depth 2, and so on. Nodes at the same depth are listed in left-to-right order. Write a program to list the nodes of a tree in level-order. Assume you have all appropriate ADT TREE operations (like PARENT, LEFTMOST-CHILD, RIGHT-SIBLING, ROOT, etc.) implemented. In your solution you may assume having some appropriate list operations as implemented well. We use the ADT queue here to make the code simple. procedure level-order(T) var level: QUEUE of nodes; v: node; begin v:= ROOT(T); MAKENULL_QUEUE(level); ENQUEUE(v, level); while not empty(level) do begin v:=FRONT(level); DEQUEUE(level); PRINT v; if LEFTMOST_CHILD(v,T)<> null then begin v:= LEFTMOST_CHILD(v,T); ENQUEUE(v,level); while RIGHT_SIBLING(v,T)<>null do begin v:=RIGHT_SIBLING(v,T); ENQUEUE(v,level); end end end end
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