tree_based_linkedlist.c

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

typedef struct node Node;

struct node {
	int data;
	Node* leftChild;
	Node* rightChild;
};

Node* initNode(int data, Node* left, Node* right) {
	Node* node = (Node*)malloc(sizeof(Node));
	if (node != NULL) {
		node->data = data;
		node->leftChild = left;
		node->rightChild = right;
	}
	return node;
}

void preorder(Node* root) {
	if (root != NULL) {
		printf("%d ", root->data);
		preorder(root->leftChild);
		preorder(root->rightChild);
	}
}

void inorder(Node* root) {
	if (root != NULL) {
		inorder(root->leftChild);
		printf("%d ", root->data);
		inorder(root->rightChild);
	}
}

void postorder(Node* root) {
	if (root != NULL) {
		postorder(root->leftChild);
		postorder(root->rightChild);
		printf("%d ", root->data);
	}
}

int main(void) {
	Node* n7 = initNode(50, NULL, NULL);
	Node* n6 = initNode(37, NULL, NULL);
	Node* n5 = initNode(23, NULL, NULL);
	Node* n4 = initNode(5, NULL, NULL);
	Node* n3 = initNode(48, n6, n7);
	Node* n2 = initNode(17, n4, n5);
	Node* n1 = initNode(30, n2, n3);

	preorder(n1);
	printf("\n");
	inorder(n1);
	printf("\n");
	postorder(n1);
	printf("\n");

	return 0;
}