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Binary Search Tree -Insertion

Sep 23, 2011 at 11:34am
agarg (2)
The problem is in this program , lnext and rnext(subtrees) are not getting correct values.They continue to be NULL even after insertion!

//BST
#include<iostream>
using namespace std;

class bst
{
public:
int data;
bst *lnext,*rnext,*root,*prev;

public:
bst()
{
lnext=rnext=root=NULL;
}

bst* addBST(bst *p)
{
if(root==NULL)//if tree is empty
{
root=p;
cout<<"\nRoot Inserted!";
return root;
}

else
{
p= insert(root,p);
return p;
}
}
bst* insert(bst *xroot, bst *newnode)
{
if(xroot==NULL)
{
xroot = newnode;


cout<<"\nnode inserted!";
return newnode;

}

if(newnode->data < xroot->data)
{
cout<<xroot->data;
cout<<"\nLEss!";
return insert(xroot->lnext,newnode);

}
else
{
cout<<"\nMore!";
return insert(xroot->rnext,newnode);

}
}

bst* minnode(bst *wroot)
{
if(wroot->lnext==NULL)
return wroot;
else
return minnode(wroot->lnext);
}


};

main()
{
bst obj,*p,*p2,*p3,*temp;
p= new bst();
p2= new bst();
p3 = new bst();
int data;

p->data=3;

p= obj.addBST(p);

p2->data=1;
p2= obj.addBST(p2);
p3->data=5;
p3= obj.addBST(p3);


temp=obj.minnode(obj.root);

cout<<"Minimum element is ::"<<temp->data;

system("pause");
return 0;
}
Sep 23, 2011 at 11:56am
mcrist (36)
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//BST
#include<iostream>
using namespace std;

class bst
{
   public:
      int data;
      bst *lnext,*rnext,*root,*prev;

   public:
      bst()
      {
         lnext=rnext=root=NULL;
      }

      bst* addBST(bst *p)
      {
         if(root==NULL)//if tree is empty
         {
            root=p;
            cout<<"\nRoot Inserted!";
            return root;
         }
         else
         {
            p= insert(root,p);
            return p;
         }
      }

      bst* insert(bst *xroot, bst *newnode) 
      {
         if(xroot==NULL)
         {
            xroot = newnode;
            cout<<"\nnode inserted!";
            return newnode;
         }

         if(newnode->data < xroot->data)
         {
            cout<<xroot->data;
            cout<<"\nLEss!"; 
            return insert(xroot->lnext,newnode);
         }
         else
         {
            cout<<"\nMore!";
            return insert(xroot->rnext,newnode);
         }
      }

      bst* minnode(bst *wroot)
      {
         if(wroot->lnext==NULL)
            return wroot;
         else
            return minnode(wroot->lnext);
      }
};

void main()
{
   bst obj,*p,*p2,*p3,*temp;
   p= new bst();
   p2= new bst();
   p3 = new bst();
   int data;

   p->data=3;

   p= obj.addBST(p);

   p2->data=1;
   p2= obj.addBST(p2);
   p3->data=5;
   p3= obj.addBST(p3);

   temp=obj.minnode(obj.root);

   cout<<"Minimum element is ::"<<temp->data;

   system("pause");
   return 0;
}
Edit & run on cpp.sh


You were missing a few brackets and this will make it more legible for others to read.
Last edited on Sep 23, 2011 at 11:59am
Sep 23, 2011 at 12:34pm
agarg (2)
Thanx mcrist,but the program is still not giving my desired output,ie Minmum element should be 1 and not 3!
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