1020. Tree Traversals (25)

Suppose that all the keys in a binary tree are distinct positive integers. Given the postorder and inorder traversal sequences, you are supposed to output the level order traversal sequence of the corresponding binary tree.

Input Specification:

Each input file contains one test case. For each case, the first line gives a positive integer N (<=30), the total number of nodes in the binary tree. The second line gives the postorder sequence and the third line gives the inorder sequence. All the numbers in a line are separated by a space.

Output Specification:

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

Sample Input:

7
2 3 1 5 7 6 4
1 2 3 4 5 6 7

Sample Output:

4 1 6 3 5 7 2
 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 
 4 typedef struct TNode *Ptr;
 5 typedef Ptr Bintree;
 6 struct TNode
 7 {
 8     int data;
 9     Bintree left;
10     Bintree right;
11 };
12 int inorder[50]; //中序
13 int post[50];   //后序
14 void Leverorder( Bintree tree);
15 Bintree Create( int in[], int post[],int n);
16 int main()
17 {
18     int n;
19     int i;
20     Bintree tree;
21     scanf("%d",&n);
22     for( i=0; i<n; i++)
23         scanf("%d",&post[i]);
24     for( i=0; i<n; i++)
25         scanf("%d",&inorder[i]);
26     tree = Create( inorder,post,n);
27     Leverorder( tree );
28     return 0;
29 }
30 
31 Bintree Create( int in[], int post[],int n)
32 {
33     if( n==0 ) return NULL;
34     int index=0;
35     Bintree temp;
36     temp = ( Bintree)malloc( sizeof(struct TNode));
37     while( index<n )
38     {
39         if( in[index]== post[n-1])
40             break;
41         index++;
42     }
43     temp->data = post[n-1];
44     temp->left = Create( in,post,index);
45     temp->right = Create( in+index+1,post+index,n-index-1);
46     return temp;
47 }
48 
49 void Leverorder( Bintree tree)
50 {
51     if( tree== NULL)
52         return ;
53     Bintree T[50];
54     int i=0,j=0;
55     int flag=0;
56     T[j++] = tree;
57     while( i<j )
58     {
59         Bintree s = T[i];
60         if( flag==0 )
61             flag=1;
62         else printf(" ");
63         printf("%d",s->data);
64         if( s->left )
65             T[j++]=s->left;
66         if( s->right)
67             T[j++]=s->right;
68         i++;
69     }
70 }

 

posted @ 2018-03-16 09:05  yuxiaoba  阅读(300)  评论(0)  编辑  收藏  举报