Tree

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

struct node
{
    int data;
    struct node *lchild;
    struct node *rchild;
};
struct node *newn(int data)
{
    struct node *newnode;
    newnode =(struct node*)malloc(sizeof(struct node));

    newnode->data=data;
    newnode->lchild=NULL;
    newnode->rchild=NULL;
    return newnode;
}

struct node *insert(struct node *root, int data)
{
     if(root == NULL)
         return newn(data);

     if(root->data<data)
         root->rchild = insert(root->rchild,data);

     if(root->data>data)
         root->lchild = insert(root->lchild,data);

     return root;
}

void inorder(struct node *root)
{
    if(root == NULL)
        return;
    inorder(root->lchild);
    printf("%d ",root->data);
    inorder(root->rchild);
}

void preorder(struct node *root)
{
    if(root == NULL)
        return;
    printf("%d ",root->data);
    inorder(root->lchild);
    inorder(root->rchild);
}

void postorder(struct node *root)
{
    if(root == NULL)
        return;
    inorder(root->lchild);
    inorder(root->rchild);
    printf("%d ",root->data);
}

int main()
{
   struct node *root = NULL;
    int data;
    while(1)
        {
            printf("\n1.insert\n2.inorder traversal\n3.preorder traversal\n4.postorder\n5.exit\n");
            printf("enter option: ");
            int choice;
            scanf("%d",&choice);
            switch (choice)
            {
            case 1 :
                printf("\nEnter the value to be inserted\n");
                scanf("%d",&data);
                root = insert(root,data);
                break;
            case 2 :
                printf("\nInorder Traversal of the Binary Tree:\n");
                inorder(root);
                break;
            case 3 :
                printf("\nPreorder Traversal of the Binary Tree:\n");
                preorder(root);
                break;
            case 4 :
                printf("\nPostorder Traversal of the Binary Tree:\n");
                postorder(root);
                break;
            case 5 :
                exit(0);
            default :
                printf("invalid option\n");
                break;
            }
        }
   return 0;
}