1064. Complete Binary Search Tree (30)

​ 时间限制

​ 100 ms

​ 内存限制

​ 65536 kB

​ 代码长度限制

​ 16000 B

​ 判题程序

​ Standard

​ 作者

​ CHEN, Yue

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

原文地址

代码如下

#include<iostream>
#include<vector>
#include<algorithm>
#include<cmath>
using namespace std;
vector<int>in,level;
int n,index=0;
void inorder(int root){
	if(root>=n) return;
	inorder(2*root+1);
	level[root]=in[index++];
	inorder(2*root+2);
}
int main(){
	scanf("%d",&n);
	in.resize(n);level.resize(n);
	for(int i=0;i<n;++i){
		scanf("%d",&in[i]);
	}
	sort(in.begin(),in.end());
	inorder(0);
	printf("%d",level[0]);
	for(int i=1;i<n;++i){
		printf(" %d",level[i]);
	}
	return 0;
}