PAT 1064. Complete Binary Search Tree （二叉树遍历）

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

题意，给你n个结点，让你遍历构造一个完全二叉树，层次遍历。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
using namespace std;
const int N = 1e3+100;
int a
,c
,n,k,d
;
void dfs(int id)
{
if(id>n) return ;
dfs(id<<1);
c[++k]=id;
dfs(id<<1|1);
}
int main()
{
int i,j;
scanf("%d",&n);
for(i=1;i<=n;i++) scanf("%d",&a[i]);
sort(a+1,a+n+1);
k=0;
dfs(1);
for(i=1;i<=n;i++) {
d[c[i]]=a[i];
}
for(i=1;i<=n;i++) {
if(i==1) printf("%d",d[i]);
else printf(" %d",d[i]);
}
printf("\n");
return 0;
}