Taking a Wild Stab at this problem:
This is like evaluating a prefix expression. We know that an expression tree also has either 0 or 2 children and the internal nodes are operators and leaf nodes are operands. In a prefix expression we try to look for the pattern "<operator><operand><operand>". If we find such a thing we evaluate it and put a placeholder for it in the string. Similarly for this, we look for the pattern NXX. where X is either L or a placeholder for a partially constructed tree. Construct the tree and replace in place of NXX a placeholder like L'. Repeat this and you will have a tree. Consider the following tree(Same from above comment) N / \ N N / \ / \ N L N L / \ / \ L L L L Prefix expression is NNNLLLNNLLL 1st NXX pattern is: NN(NLL)LNNLLL construct a tree for it and replace in the String as L' to get NNL'LNNLLL 2nd NXX: N(NL'L)NNLLL =>NL'NNLLL 3rd NXX: NL'N(NLL)L => NL'NL'L 4th NXX NL'(NL'L) => NL'L' (Final result) Basically we are constructing the tree in a bottom up fashion. On Jan 14, 10:20 am, Decipher <ankurseth...@gmail.com> wrote: > A special type of tree is given, where all leaf are marked with L and others > are marked with N. every node can have 0 or at most 2 nodes. Trees preorder > traversal is given give a algorithm to build tree from this traversal. -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.