1064 Complete Binary Search Tree (30分)
A Binary Search Tree (BST) is recursively defined as a binary tree which has the following properties:
The left subtree of a node contains only nodes with keys less than the node’s key.
The right subtree of a node contains only nodes with keys greater than or equal to the node’s key.
Both the left and right subtrees must also be binary search trees.
A Complete Binary Tree (CBT) is a tree that is completely filled, with the possible exception of the bottom level, which is filled from left to right.
Now given a sequence of distinct non-negative integer keys, a unique BST can be constructed if it is required that the tree must also be a CBT. You are supposed to output the level order traversal sequence of this BST.
Input Specification:

Each input file contains one test case. For each case, the first line contains a positive integer N (≤1000). Then N distinct non-negative integer keys are given in the next line. All the numbers in a line are separated by a space and are no greater than 2000.
Output Specification:

For each test case, print in one line the level order traversal sequence of the corresponding complete binary search tree. All the numbers in a line must be separated by a space, and there must be no extra space at the end of the line.
Sample Input:

10
1 2 3 4 5 6 7 8 9 0
Sample Output:

6 3 8 1 5 7 9 0 2 4
关键：完全二叉搜索树的中序遍历就是从小到大排序输出

#include<iostream>
#include<algorithm>
using namespace std;
int cnt = 0;
int bst[1005], l[1005];//bst数组存储原始数据，l存储中序遍历结果。
int n;
void dfs(int root)
{if (root < n)//root小于节点数{dfs(root * 2 + 1);l[root] = bst[cnt++];dfs(root * 2 + 2);}
}
int main()
{cin >> n;for (int i = 0; i < n; i++){cin >> bst[i];}sort(bst, bst + n);//排序dfs(0);//从根节点进行深搜for (int i = 0; i < n; i++){if (i != 0)cout << " ";cout << l[i];}
}