Easy JAVA solution using Two Queues

[ujjwal-singh_164]

/**

• Definition for binary tree with next pointer.

• public class TreeLinkNode {

• int val;
  

• TreeLinkNode left, right, next;
  

• TreeLinkNode(int x) { val = x; }
  

• }
  */
  public class Solution {
  public void connect(TreeLinkNode root) {
  Queue q = new LinkedList();
  Queue p = new LinkedList();
  q.add(root);

  while(!q.isEmpty()|| !p.isEmpty()){
      while(q.size()>0){
          if(q.peek().left!=null){
              p.add(q.peek().left);
          }
          
          if(q.peek().right!=null){
              p.add(q.peek().right);
          }
          if(q.size()>=2){
           q.poll().next=q.peek();
          }else
          q.poll();
      }
      while(p.size()>0){
          if(p.peek().left!=null){
              q.add(p.peek().left);
          }
          
          if(p.peek().right!=null){
              q.add(p.peek().right);
          }
          if(p.size()>=2){
           p.remove().next=p.peek();
          }else
          p.poll();
  }
  }
  

}
}