A binary tree problem - Populating next right pointers in each node

Source

void connect(Node* p) {

if (p == NULL)

return;

if (p->leftChild == NULL || p->rightChild == NULL)

return;

Node* rightSibling;

Node* p1 = p;

while (p1) {

if (p1->nextRight)

rightSibling = p1->nextRight->leftChild;

else

rightSibling = NULL;

p1->leftChild->nextRight = p1->rightChild;

p1->rightChild->nextRight = rightSibling;

p1 = p1->nextRight;

}

connect(p->leftChild);

}