#### 116 | Populating Next Right Pointers in Each Node #### BFS Solution ```python class Solution(object): def connect(self, root): if not root: return queue = [root] while queue: curr = queue.pop(0) if curr.left and curr.right: curr.left.next = curr.right if curr.next: curr.right.next = curr.next.left queue.append(curr.left) queue.append(curr.right) ```  ---- 