CareerCup

Most probably this qus is for tree/graph right?

we can use Kth order statistics to get the first K elements near to it..

1) Scan the tree to look for the node and push all parent nodes encountered in the path to a stack S
2) Write a function to find nodes at K distance which are child of this node (simple DFS). Lets call that function kChild(node)
3) Now pop the parent of the node and find out the k -1 distance child nodes of it.
4) Repeat the process till the stack is empty.

void findbelow(struct tnode *root,int level,int k)
{
     if(root==NULL)
        return;
     if(level==k)
     {
        printf("%d\t",root->val);
        return;
     }
     findbelow(root->left,level+1,k);
     findbelow(root->right,level+1,k);
}

void findabove(struct tnode *root,struct tnode *node,int level,int k)
{
     static int vector=0;
     if(root==NULL)
        return;
     findabove(root->left,node,level+1,k);
     findabove(root->right,node,level+1,k);
     if(root==node)
        vector = vector | 1<<level;
     if(vector & 1<<(level+k))
     {
        vector = vector ^ 1<<(level+k);
        printf("%d\t",root->val);
     }
}

BFS should do the trick!

use this one
suppose pointer *p is in current position

p=p + ((k * sizeof(struct node) ) - (k * work_size));