pat1064. Complete Binary Search Tree (30)

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

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提交代码

 #include<cstdio>
 #include<stack>
 #include<algorithm>
 #include<iostream>
 #include<stack>
 #include<set>
 #include<map>
 #include<cmath>
 using namespace std;
 int line[],tree[];
 void Build(int *line,int *tree,int n,int cur){
     if(!n){
         return;
     }
     int h=log(n)/log();
     int x=n-(pow(,h)-);

     //cout<<"x: "<<x<<endl;

     if(x>pow(,h-)){
        x=pow(,h-);
     }

     //cout<<"x: "<<x<<endl;

     int l=pow(,h-)+x-;

     //cout<<"l:  "<<l<<endl;

     tree[cur]=line[l];
     Build(line,tree,l,cur*+);
     Build(line+l+,tree,n-l-,cur*+);
 }
 int main(){
     //freopen("D:\\INPUT.txt","r",stdin);
     int n,i;
     scanf("%d",&n);
     for(i=;i<n;i++){
         scanf("%d",&line[i]);
     }
     sort(line,line+n);
     Build(line,tree,n,);
     printf("%d",tree[]);
     for(i=;i<n;i++){
         printf(" %d",tree[i]);
     }
     printf("\n");
     return ;
 }