Thread: C++ Binary Tree Basics

Code:

//Declare Data Structure
struct CP {
    int id;         //ID of the Node
    int data;       //Data of the Node
    CP * left;      //Pointer to the Left Subtree 
    CP * right;     //Pointer to the Right Subtree
};

typedef CP * CPPtr;

I have a structure of tree that looks like this. Without changing the structure of tree, I am required to write a function that return's the depth of a node given it's id. (id is a unique number that represents the node). i.e. something like int getDepth(CPPtr tree,int id).

Can anyone help me? Your help would be much appreciated.

my idea is simply have a function that checks the id of a node by taking it's pointer => nodeID
Then I traverse the tree until it found nodeID(tree pointer) == id. Then I calculate the depth by using ldepth and rdepth.
Initially i intend to do it in 1 function using recursion, but failed to do so.
So i used 2 functions,1 doing the recursion and another just takes the result and process.
However, it never really worked

Code:

int nodeDepth(CPPtr tree, int id) 
{     
   int lDepth=0,rDepth=0;     
   nodeDepth_Helper(tree,id,lDepth,rDepth);    
   cout<<"lDepth "<<lDepth<<endl;   
   cout<<"rDepth "<<rDepth<<endl;   
   return min(lDepth,rDepth); 
}  

//Define nodeDepth_Helper to do the actual recursion to find lDepth and rDepth 
void nodeDepth_Helper(CPPtr tree, int id, int& lDepth,int& rDepth)
{    
if (tree != NULL)    
{      
     if (nodeID(tree)==id)             
            return;          
    else       
    {            
        lDepth=lDepth+1;     
        nodeDepth_Helper(tree->left,id,lDepth,rDepth);      
        rDepth=rDepth+1;   
        nodeDepth_Helper(tree->right,id,lDepth,rDepth);          
     }    
} 
}