Second largest element in a binary search tree.

How to find out the second largest largest element in a binary search tree?

If a BST have atleast 2 nodes then…
Second largest Element in a BST is the parent of Largest Element of BST.
ie its the parent of rightmost node.
If a BST don’t have right subtree Second largest element is the rightmost child of left subtree.

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void print2ndLargest ( node * root)
{
    if(root==NULL||(root->Rchild==NULL&&root->Lchild==NULL))
    {
        cout<<"2nd Largest Not possible \n";
        return;
    }
    if(root->Rchild==NULL)
    {
        node * temp;
        temp=root->Lchild;
        while(temp->Rchild!=NULL)
        {
            temp=temp->Rchild;
        }
        cout<<"2nd Largest : "<< temp->info;
        return;
    }
    node * parentt;
    node * temp;
    parentt=root;
    temp=root->Rchild;
    while(temp->Rchild!=NULL)
    {
        parentt=temp;
        temp=temp->Rchild;
    }
    cout<< "2nd Largest : " << parentt->info;  //Largest is : temp->info
}


^ Hope this helps.

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