
ZOJ Problem Set  1167
Trees are fundamental in many branches of computer science. Current stateofthe art parallel computers such as Thinking Machines' CM5 are based on fat trees. Quad and octaltrees are fundamental to many algorithms in computer graphics. This problem involves building and traversing binary trees. Given a sequence of binary trees, you are to write a program that prints a levelorder traversal of each tree. In this problem each node of a binary tree contains a positive integer and all binary trees have fewer than 256 nodes. In a levelorder traversal of a tree, the data in all nodes at a given level are printed in lefttoright order and all nodes at level k are printed before all nodes at level k+1. For example, a level order traversal of the tree
In this problem a binary tree is specified by a sequence of pairs (n,s) where n is the value at the node whose path from the root is given by the string s. A path is given be a sequence of L's and R's where L indicates a left branch and R indicates a right branch. In the tree diagrammed above, the node containing 13 is specified by (13,RL), and the node containing 2 is specified by (2,LLR). The root node is specified by (5,) where the empty string indicates the path from the root to itself. A binary tree is considered to be completely specified if every node on all roottonode paths in the tree is given a value exactly once.
All nodes contain a positive integer. Every tree in the input will consist of at least one node and no more than 256 nodes. Input is terminated by endoffile.
Sample Input (11,LL) (7,LLL) (8,R) Sample Output 5 4 8 11 13 4 7 2 1 Source: Zhejiang University Local Contest 2002, Warmup 