4.4 given a binary tree, design an algorithm which creates a linked list of all the nodes at each depth

gistfile1.java

void createLinkedListFromBT(TreeNode r,ArrayList al, int level){
  if(r==null) return;
 LinkedList<TreeNode> temp=null;
 if(al.size()==level){
   temp=new LinkedList<TreeNode>();
   al.add(temp);
   
 }else if(level<al.size()){
   temp=al.get(level)
   
   
 }
 else{
   
   return;
 }
temp.add(r);
createLinkedListFromBT(r.left,al, level+1);
createLinkedListFromBT(r.right,al, level+1);
 

  
  }
 ArrayList<LinkedList<TreeNode>> createLinkedlist(TreeNode r){
    if(r!=null){
      
      ArrayList<LinkedList<TreeNode>> al=new Arraylist<LinkedLis<TreeNode>>();
      createLinkedListFromBT(r, al, 0);
      return al;
    }
    return null
    
  }