MINIMUM DISTANCE BETWEEN NODES IN TREE

Distance b/w two nodes in tree such as:

                                                              1
                                     2                                                  3
                      4                        5                           6                            7
             8             9          10          11           12           13         14           15

Ex.: 
 Distance b/w nodes 8 and 15 =>>6   
        ( 8->4->2->1->3->7->15)    6 vertices

 Distance b/w nodes 8 and 10=>>3

     while(i!=j)
     {
                if(i>j)
                     {
                        i=i/2;
                         count++;
                      }
                else
                    {
                       j=j/2;
                       count++;
                    }
      }

where i is intial node and j is final node :)