1627Trees Made to Order

1627   Trees Made to Order

题目描述

We can number binary trees using the following scheme:

The empty tree is numbered 0.
The single-node tree is numbered 1.
All binary trees having m nodes have numbers less than all those having m+1 nodes.
Any binary tree having m nodes with left and right subtrees L and R is numbered n such that all trees having m nodes numbered > n have either
  Left subtrees numbered higher than L, or
  A left subtree = L and a right subtree numbered higher than R.

The first 10 binary trees and tree number 20 in this sequence are shown below:

Your job for this problem is to output a binary tree when given its order number.

输入格式:

Input consists of multiple problem instances. Each instance consists of a single integer n, where 1 <= n <= 500,000,000. A value of n = 0 terminates input. (Note that this means you will never have to output the empty tree.)

输出格式:

For each problem instance, you should output one line containing the tree corresponding to the order number for that instance. To print out the tree, use the following scheme:

A tree with no children should be output as X.
A tree with left and right subtrees L and R should be output as (L')X(R'), where L' and R' are the representations of L and R.
  If L is empty, just output X(R').
  If R is empty, just output (L')X.

输入样例 复制
1
20
31117532
0
输出样例 复制
X
((X)X(X))X
(X(X(((X(X))X(X))X(X))))X(((X((X)X((X)X)))X)X)

说明

1
1
通过提交
时空限制2000ms/64mb
题目来源
评测方式在线评测
题目类型
难        度