Binary tree INCOMPLETE.c

#include <stdio.h>
#include <stdlib.h>
void menu(void);
struct node{
	int i;
	struct node *lc;
	struct node *rc;
}*root;

void buildtree(struct node *ptr){
	struct node *lcptr,*rcptr;
	int c;
	if(ptr != NULL){
		printf("Enter item : ");
		scanf("%d",&ptr->i);
		printf("Does %d has a Left child ? (1/0) : ",ptr->i);
		scanf("%d",&c);
		if(c==1){
			lcptr = (struct node *)malloc(sizeof(struct node));
			ptr->lc = lcptr;
			buildtree(lcptr);
			}
		else{
			lcptr = NULL;
			ptr->lc = NULL;
			buildtree(lcptr);
		}
		printf("Does %d has a right child ? (1/0) : ",ptr->i);
		scanf("%d",&c);
		if(c==1){
			rcptr = (struct node *)malloc(sizeof(struct node));
			ptr->rc = rcptr;
			buildtree(rcptr);
			}
		else{
			rcptr = NULL;
			ptr->rc = NULL;
			buildtree(rcptr);
		}
}
}

void preorder(struct node *ptr){
	if(ptr !=NULL){
		printf("%d ",ptr->i);
		preorder(ptr->lc);
		preorder(ptr->rc);
	}
}

void inorder(struct node *ptr){
	if(ptr !=NULL){
    inorder(ptr->lc);
	  printf("%d ",ptr->i);
    inorder(ptr->rc);
	}
}

void postorder(struct node *ptr){
	if(ptr !=NULL){
    postorder(ptr->lc);
    postorder(ptr->rc);
 	  printf("%d ",ptr->i);
	}
}

void display(struct node *ptr,int l){
     int i;
     if(ptr != NULL){
            display(ptr->rc,l+5);
            for(i=0;i<l;i++){
               printf("  ");
                              }
            printf("%d\n",ptr->i);
            display(ptr->lc,l+5);
            }
          }
          
void search(struct node *ptr,int item){
          if(ptr->lc != NULL||ptr->rc != NULL){
            if((ptr->lc->i==item)||(ptr->rc->i==item)){
                printf("\nItem found as child of %d",ptr->i);
                return ;
                                                   }
            
            else{
            search(ptr->lc,item);
            search(ptr->rc,item);
            }
     
      printf("\nItem not found");       
     }
}
void submenu(void){
     int op,item;
     printf("\n1 for Search\n2 for Preordern\n3 for Inorder\n4 for Postorder\n5 for Main Menu");
     printf("\nEnter Choice : ");
     scanf("%d",&op);
     switch(op){
           case 1:
                printf("\nEnter item: ");
                scanf("%d",&item);
                search(root,item);
                submenu();
           break;
           case 2:
                preorder(root);
                printf("\n");
                submenu();
           break;
           case 3:
                inorder(root);
                printf("\n");
                submenu();
           break;
           case 4:
                postorder(root);
                printf("\n");
                submenu();
           break;
           case 5:
                menu();
           break;
           default:
                   printf("\nInvalid option");
           break;
                }
     
     }
     
void menu(void){
     int op;
     printf("\nPress 1 for BUILD TREE\nPress 2 for display\nPress 3 to EXIT");
     printf("\nEnter Choice: ");
     scanf("%d",&op);
     switch(op){
                case 1:
                     if(root==NULL){
                     root = (struct node*)malloc(sizeof(struct node));
                     buildtree(root);
                     }
                     submenu();
                     menu();     
                break;
                case 2:
                     display(root,0);
                break;
                case 3:
                     return ;
                break;
                default:
                        printf("\nInvalid Option");
                        menu();
                }
  }     
int main(){
    menu();
    return 0;
    }