trees

//
//  main.c
//  trees
//
//  Created by Mahmoud ElMarakshy on 4/28/13.
//  Copyright (c) 2013 Mahmoud ElMarakshy. All rights reserved.
//

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

struct node{
    char * data;
    struct node *left;
    struct node *right;

}*root=NULL,*temp;
struct node* insert(struct node *root,char x[]);
struct node *  delete(struct node*ptr,char a[]);
void traverse(struct node*ptr);
struct node *  Findmin(struct node*ptr);
void search(struct node *root,char x[]);


int main(){
    int choice;
    char a[10];

    printf("enter choice(1 to insert , 2 insert delet , 3 traverse ):");
    scanf("%d",&choice);

    while(choice!=-1){
        switch (choice) {
            case 1:
                printf("enter data:");
                scanf("%s",a);
                root=insert(root,a);
                break;
            case 2:
                printf("enter data:");
                scanf("%s",a);
                delete(root,a);
                break;
            case 3:
                traverse(root);
                break;
            case 4:
                printf("enter data:");
                scanf("%s",a);
                search(root,a);
            default:
                break;
        }

        printf("enter choice:");
        scanf("%d",&choice);
    }

}

struct node * insert(struct node *root, char x[])
{int a;

    if(!root)
    {
        root=(struct node*)malloc(sizeof(struct node));
        root->data = x;
        root->left = NULL;
        root->right = NULL;
        printf("1\n");
        return(root);
    }
    if((a=strcmp(root->data,x))>0){
        root->left = insert(root->left,x);
}
    else
    {
        if(strcmp(root->data,x)<0)
            root->right = insert(root->right,x);
    }
    return(root);
}

void traverse(struct node*ptr){
    if(ptr!=NULL){
        traverse(ptr->left);
        printf("%s",ptr->data);
        traverse(ptr->right);
    }
}
struct node *  delete(struct node*T,char a[])
{
    if(T==NULL) ; // element is not found in the tree
    else if(strcmp(a,T->data)<0)
        T->left = delete(T->left,a);
    else if(strcmp(a,T->data)>0)
        T->right = delete(T->right,a);
    else if((T->left)!=NULL && (T->right)!=NULL) { // node with 2 children
        temp = Findmin(T->right);
        T->data = temp->data;
        T->right = delete(T->right,T->data); }
    else {
        temp = T;
        if(T->left==NULL)
            T = T->right;
        else if(T->right==NULL)
            T = T->left;
        // free(temp);
    }
    return T; }
struct node *  Findmin(struct node*ptr){
    if((ptr->left)==NULL){
        printf("min is :%s",ptr->data);
        return ptr;
    }
    else
        return Findmin(ptr->left);

}
void search(struct node *ptr,char x[])
{
    while (ptr!=NULL) {

        if(strcmp(x,ptr->data)==0){
            printf("found data is :%s\n",ptr->data);

            return;
        }
        else{
            if(strcmp(x,ptr->data)<0)
                ptr=ptr->left;
            else
                ptr=ptr->right;
        }
    }
    printf("not found\n");
}