Tree traversal (preorder,inorder,postorder) print result change

Question

#include <stdio.h>  
#include <stdlib.h>  
#include <memory.h>  

void preorder(char tree[], int i)    
{  
   if(tree[i] != '\0')  
   {  
        printf("%c", tree[i]);
        preorder(tree, i*2);  
        preorder(tree, i*2+1);  
  }  
}  
void inorder(char tree[], int i)  
{  
   if(tree[i] != '\0')  
   {  
        inorder(tree, i*2);  
        printf("%c", tree[i]);  
        inorder(tree, i*2+1);  
  }  
}  
void postorder(char tree[], int i) 
{  
   if(tree[i] != '\0')  
   {  
        postorder(tree, i*2);  
        postorder(tree, i*2+1);  
        printf("%c", tree[i]);  
  }  
}  
void main()  
{  

   char ArrayTree[36] = { 0,'A','B','C','D','E','F','G','H','I','J','K',0, };  
   printf("\n preorder : ");  
   preorder(ArrayTree, 1);  
   printf("\n inorder: ");  
   inorder(ArrayTree, 1);  
   printf("\n postorder: ");  
   postorder(ArrayTree, 1);  
   getchar();  
} 

Current Print result

preorder: ABDHIEJKCFG / inorder: HDIBJEKAFCG / postorder: HIDJKEBFGCA /

But I want to print like this

preoder: ABDHEIJCFGK / inorder: HDBIEJAFCGK / postorder: HDIJEBFKGCA /

Binary Tree image

How to change it?

Answer 1

The code looks correct but your data is wrong. It doesn't represent the tree in your diagram. For example, the right sibling of 'H' should be 0 (or NULL).

A corrected array looks like:

char ArrayTree[32] = { 0,'A','B','C','D','E','F','G','H',0,'I','J',0,0,0,'K' };

The size only needs to be 32 to contain a complete tree of height 5 (plus the unused 0 index).