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1) can any one give me solution for this pleaseee
Using the examples in Figures 24-6 and 24-7 to suggest algorithms, implement iterator classes for preorder,
postorder, and level-order traversals of a binary tree.Begin by writing iterative versions of the traversals similar to the method interativeInorderTraverse given in segment 24.13
FIGURE 24-6 Using a stack to traverse a binary tree in (a) preorder; (b) postorder (aTraversal order a Stack after cach puslh or pop (b) Traversal order Stack after each puslh or pop
Expert Answer
It is a simple algorithmic implementation
// class stack has four operation: 1. push( T x)
// 2. pop()
// 3. top()
// 4. size()
// class queue has four operation: 1. push( T x)
// 2. pop()
// 3. top()
// 4. size()
// treenode{
// int val;
// treenode* left,right;
//}
class BinaryTree{
queue<treenode> q;
class preorder{
stack<treenode> s;
public:
preorder(){
this->s.push(treehead);
}
preorder(treenode* node){
this->s.push(node);
}
boolean hasNext(){
if(this->s.size()==0)
return false;
else
return true;
}
E Next(){
if(this->s.size() == 0)
throw(error);
else
{
treenode* node=this->s.top();
this->s.pop();
if(node->right!=null)
this->s.push(node->right);
if(node->left!=null)
this->s.push(node->left);
return node;
}
}
void remove(){
if(this->s.size)
}
}
class postorder{
stack<treenode> s;
public:
postorder(){
treenode* cur=treehead;
if(treehead!=null)
this->s.push(treehead);
cur=this->s.top();
while(cur-left!=null&&cur->right!=null){
if(cur->right!=null){
this->s.push(cur->left)
}
if(cur->left!=null){
this->s.push(cur->left)
}
cur=this->s.top();
}
}
postorder(treenode* node){
this->s.push(node);
cur=this->s.top();
while(cur-left!=null&&cur->right!=null){
if(cur->right!=null){
this->s.push(cur->left)
}
if(cur->left!=null){
this->s.push(cur->left)
}
cur=this->s.top();
}
}
boolean hasNext(){
if(this->s.size()==0)
return false;
else
return true;
}
E Next(){
if(this->s.size() == 0)
throw(error);
else
{
treenode* node = this->s.top();
this->s.pop();
cur=this->s.top();
if(cur->left!=node && cur->right!=node){
while(cur-left!=null && cur->right!=null){
if(cur->right!=null){
this->s.push(cur->left)
}
if(cur->left!=null){
this->s.push(cur->left)
}
cur=this->s.top();
}
}
}
return node;
}
}
class levelorder{
queue<treenode> q;
public:
preorder(){
this->q.push(treehead);
}
preorder(treenode* node){
this->q.push(node);
}
boolean hasNext(){
if(this->q.size()==0)
return false;
else
return true;
}
E Next(){
if(this->q.size() == 0)
throw(error);
else
{
treenode* node=this->q.top();
this->q.pop();
if(node->right!=null)
this->q.push(node->right);
if(node->left!=null)
this->q.push(node->left);
return node;
}
}
void remove(){
if(this->q.size()){
this->q.pop();
}
}
}
}
