Binary tree.c

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

struct Node
{
    char data;
    struct Node *lchild;
    struct Node *rchild;
};

struct Node *root=NULL;

void Inorder(struct Node *p)
{
    if(p)
    {
        Inorder(p->lchild);
        printf("%c ",p->data);
        Inorder(p->rchild);
    }
}

void Preorder(struct Node *p)
{
 if(p)
 {
 printf("%c ",p->data);
 Preorder(p->lchild);
 Preorder(p->rchild);
 }
}

void Postorder(struct Node *p)
{
    if(p)
    {
        Postorder(p->lchild);
        Postorder(p->rchild);
        printf("%c ",p->data);
    }
}


struct Node * insert(struct Node *p,char key)
{
    struct Node *t;

    if(p==NULL)
    {
        t=(struct Node *)malloc(sizeof(struct Node));
        t->data=key;
        t->lchild=t->rchild=NULL;
        return t;
    }

    if((int)key<(int)p->data)
        p->lchild=insert(p->lchild,key);
    else if((int)key>(int)p->data)
        p->rchild=insert(p->rchild,key);
    return p;
}

struct Node * RInsert(struct Node *p,char key)
{
    struct Node *t=NULL;
    if(p==NULL)
    {
        t=(struct Node *)malloc(sizeof(struct Node));
        t->data=key;
        t->lchild=t->rchild=NULL;
        return t;
    }
    if(key<p->data)
        p->lchild=RInsert(p->lchild,key);
    else if(key>p->data)
        p->rchild=RInsert(p->rchild,key);
    return p;
}

int Height(struct Node *p)
{
    int x,y;
    int count=0;
    if(p==NULL)
        return 0;
        x=Height(p->lchild);
        y=Height(p->rchild);
        return x>y?x+1:y+1;

}

struct Node *InPre(struct Node *p)
{
    while(p && p->rchild!=NULL)
    {
        p=p->rchild;
    }
    return p;
}

struct Node *Insucc(struct Node *p)
{
    while(p && p->lchild!=NULL)
    {
        p=p->lchild;
    }
    return p;
}
struct Node *Delete(struct Node *p,char key)
{
    struct Node *q;
    if(p==NULL)
        return NULL;
    if(p->lchild==NULL && p->rchild==NULL)
    {
        if(p==root)
            root=NULL;
        free(p);
        return NULL;
    }
    if((int)key<(int)p->data)
        p->lchild=Delete(p->lchild,key);
    else if((int)key>(int)p->data)
        p->rchild=Delete(p->rchild,key);
    else{
        if(Height(p->lchild)>Height(p->rchild))
        {
            q=InPre(p->lchild);
            p->data=q->data;
            p->lchild=Delete(p->lchild,q->data);
        }
        else{
            q=Insucc(p->rchild);
            p->data=q->data;
            p->rchild=Delete(p->rchild,q->data);
        }
    }
    return p;
}

void search(struct Node *p,char key)
{
    while(p){
    if(p->data==key){
        printf("\n%c found in the tree",key);
        break;}
    else if(key>p->data)
        p=p->rchild;
    else if(key<p->data)
        p=p->lchild;
    }

    if(p==NULL)
    printf("\nElement not found");
}



int main()
{
    //int level;
    //printf("\nEnter the level of tree: ");
//    scanf("%d",&level);
     printf("\nEnter the root element: ");
     char n;
     scanf("%c",&n);

     root=insert(root,n);

     char k;
     int r=0;
     printf("\nEnter the value to be inserted in binary tree: ");
     while(k!='e')
     {
        // printf("\nEnter the value to be inserted in binary tree: ");
        //program terminates when an alphabet is entered in small letter
         scanf("%c",&k);
         if(k>='a' && k<='z')
            break;
         insert(root,k);
         r++;
     }
     printf("Prorder: ");
     Preorder(root);
     printf("\n");
     printf("Postorder: ");
     Postorder(root);
     printf("\n");
     printf("Inorder: ");
     Inorder(root);
    // search(root,'A');
     //Delete(root,'B');
     //printf("\n");
     //Inorder(root);
}