/*
BST: Binary SeaRCh Tree, LC: Left Child, RC: Right Child, TN: Temp Node, POT: Pre-Order Traversal,IOT: In-Order Traversal,PST: Post-Order Traversal,
*/
#include <stdio.h>
#include <stdlib.h>
struct node {
int data;
struct node *LC;
struct node *RC;
};
struct node *root = NULL;
void insert(int data) {
struct node *TN = (struct node*) malloc(sizeof(struct node));
struct node *current;
struct node *parent;
TN->data = data;
TN->LC = NULL;
TN->RC = NULL;
if(root == NULL) { //if tree is empty
root = TN;
} else {
current = root;
parent = NULL;
while(1) {
parent = current;
if(data < parent->data) {//go to left of the tree
current = current->LC;
if(current == NULL) {//insert to the left
parent->LC = TN;
return;
}
} //go to right of the tree
else {
current = current->RC;
if(current == NULL) {//insert to the right
parent->RC = TN;
return;
}
}
}
}
}
void POT(struct node* root) {
if(root != NULL) {
printf(“%d “,root->data);
POT(root->LC);
POT(root->RC);
}
}
void IOT(struct node* root) {
if(root != NULL) {
IOT(root->LC);
printf(“%d “,root->data);
IOT(root->RC);
}
}
void PST(struct node* root) {
if(root != NULL) {
PST(root->LC);
PST(root->RC);
printf(“%d “, root->data);
}
}
int main() {
int x;
printf(“Enter tree nodes, -1 for exit.”);
scanf(“%d”,&x);
while(x != -1){
insert(x);
scanf(“%d”,&x);
}
printf(“\nPreorder traversal: “);
POT(root);
printf(“\nInorder traversal: “);
IOT(root);
printf(“\nPost order traversal: “);
PST(root);
return 0;
}
