二叉樹的遞迴建立

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 
 4 struct tree
 5 {
 6     int data;
 7     struct tree* left;
 8     struct tree* right;
 9 };
10 
11 typedef struct tree treenode;
12 typedef treenode* btree;
13 
14 btree createbtree(int* data,int pos)
15 {
16     btree newnode;
 
17     
18     if(data[pos] == 0 || pos > 15)
19         return NULL;
20     else
21     {
22         newnode = (btree)malloc(sizeof(treenode));
23         newnode->data = data[pos];
24         
25         newnode->left = createbtree(data,2*pos);
26         newnode->right = createbtree(data,2
 
*pos + 1);
27         return newnode;
28     }
29 }
30 
31 void printbtree(btree ptr)
32 {
33     if(ptr != NULL)
34     {
35         printbtree(ptr->left);
36         printf("[%2d]",ptr->data);
37         printbtree(ptr->right);
38     }
39 }
40 
41 int main()
42 {
43     btree root = NULL;
 
44     int i;
45     
46     int data[16] = {0,5,4,6,2,0,0,8,1,3,0,0,0,0,7,9};
47     root = createbtree(data,1);
48     printf("陣列的節點內容  \n");
49     for(i = 1;i < 16;i++)
50         printf("[%2d]",data[i]);
51     printf("\n");
52     printf("樹的結點內容  \n");
53     printbtree(root);
54     printf("\n");
55     return 0;
56 }