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//Threaded Binary Search tree

#include#include#include

#include

int count=0;

typedef struct node node;

struct node{int data,lt,rt;node* llink;node* rlink;};

void preorder(node* );void inorder(node* );void postorder(node* );node *threading();

main(void){

int ch;node *root=NULL;

do

{

printf("\n1:Create threaded BST tree\n2:Preorder\n3:Inorder\n4:Postorder\n5:Exit\n");scanf("%d",&ch);

switch(ch){

case 1:root=threading();

break;

case 2:preorder(root);

break;

case 3:inorder(root);

break;

case 4:postorder(root);

break;

case 5:exit(0);

break;

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}}while(ch!=5);

getch();}

node *threading()

{

int n,num,x=0;

node* root,*link,*link1,*temp;

printf("\nHow many nodes do you want ?\n");scanf("%d",&n);count=n;

root=(node*)malloc(sizeof(struct node));

printf("Enter the data\n");scanf("%d",&(root->data));

root->rt=0;root->lt=0;root->llink=NULL;root->rlink=NULL;link=root;n--;

while(n--){

printf("Enter the data\n");scanf("%d",&num);

link=root;

while(link){

if((num>link->data)&&(link->rt!=1)){x=0;link1=link;link=link->rlink;}

else if((num>link->data)&&(link->rt==1)){x=0;link1=link;link=link->rlink;break;}

else if((numdata)&&(link->lt!=1)){

x=1;link1=link;link=link->llink;

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}

else if((numdata)&&(link->lt==1)){x=1;link1=link;link=link->llink;

break;}

} //End of inner loop

if(x==0) //for right branch{

temp=(node*)malloc(sizeof(node));temp->data=num;temp->lt=1;temp->llink=link1;

if(link1->rt==1)

{temp->rlink=link1->rlink;temp->rt=1;link1->rt=0;}

else{temp->rt=0;temp->rlink=NULL;}

link1->rlink=temp;

}

else{

temp=(node*)malloc(sizeof(node)); //left branchtemp->data=num;temp->rt=1;temp->rlink=link1;

if(link1->lt==1){temp->lt=1;temp->llink=link1->llink;link1->lt=0;}

else{temp->lt=0;temp->llink=NULL;}

link1->llink=temp;

}

}return root;

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}//..........................Preorder traversal.................................

void preorder(node* link){while(link)

{

while(link->llink!=NULL && link->lt==0){printf(" %d ",link->data);link=link->llink;}

printf("%d ",link->data);while(link->rt==1)

{link=link->rlink;}link=link->rlink;

}}

//.........................Inorder Traversal...................................

void inorder(node* link){while(link)

{while(link->llink!=NULL && link->lt==0)link=link->llink;

printf(" %d ",link->data);

while(link->rt==1){link=link->rlink;printf("%d ",link->data);}link=link->rlink;

}}

//.........................Postorder Traversal.................................

void postorder(node* link){int *store,i=0;

store=(int *)malloc(count * sizeof(int));

while(i!=count){while(link->rt==0 && link->rlink!=NULL)

{*(store+i)=link->data;i++;link=link->rlink;

}

*(store+i)=link->data;

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i++;

while(link->lt==1){link=link->llink;

}link=link->llink;

}for(i=count-1;i>=0;i--)

{printf(" %d ",*(store+i));

}}/*..........................................................................*/