ISI2014-PCB-CS-2a

Question

Let $B$ be a rooted binary tree of $n$ nodes. Two nodes of $B$ are said to be a sibling pair if they are the children of the same parent. For example, given the binary tree in Figure 1, the sibling pairs are (2, 3) and (6, 7). Design an $O(n)$ time algorithm that prints all the sibling pairs of $B$.

Comments

A simple traversal will work, just need a little bit of modification.

Answer 1

int siblingpairs( Struct node *root ){

if(root==Null)

return  0;

if(root → lc==Null || root →rc==Null)

{
return 0;

}

if(root → lc==Null && root →rc==Null)

{
return 0;

}

else{

LS= siblingpairs(root→lc);

RS=siblingpairs(root→rc);

return (root→lc,root→rc);

}

}