Question

C program that demonstrate tree traversal. see for the sample output.

Sample Output:

How many node do you have in your tree : 5

Enter root: 20
if you want to add to the left press 0 otherwise press 1
answer: 0
Enter next node: 10
if you want to add to the left press 0 otherwise press 1
answer: 0
Enter next node: 8
if you want to add to the left press 0 otherwise press 1
answer: 0
Enter next node: 15
if you want to add to the left press 0 otherwise press 1
answer: 1
Enter next node: 21

Display tree

20
/ \
10 21
/
8
/
5

Preorder – 20, 10, 8, 5, 21
       Inorder – 5, 8, 10, 20, 21
       Postorder – 5, 8, 10, 21, 20

** COMMENT CODE PLEASE**

Answer 1

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

struct node {
int data;
struct node *left;
struct node *right;
};

typedef struct node tree;

tree *root = NULL;

tree* newnode(int data) {

tree *new = NULL;
new = (tree *)malloc(sizeof(tree));

new->data = data;
new->left = NULL;
new->right = NULL;

return(new);
}

void preorder(tree *root) {

if(root == NULL) {return;}

printf("%d ",root->data);
preorder(root->left);
preorder(root->right);
}

void inorder(tree *root) {

if(root == NULL) {return;}

inorder(root->left);
printf("%d ",root->data);
inorder(root->right);
}

void postorder(tree *root) {

if(root == NULL) {return;}

postorder(root->left);
postorder(root->right);
printf("%d ",root->data);
}

int main() {
root = newnode(20);
root->left = newnode(10);
root->right = newnode(21);
root->left->left = newnode(8);
root->left->left->left = newnode(15);
printf("Preorder traversal of binary tree is : ");
preorder(root);
printf("\n");
printf("Inorder traversal of binary tree is : ");
inorder(root);
printf("\n");
printf("Postorder traversal of binary tree is : ");
postorder(root);

getchar();
return 0;
}