第110题：平衡二叉树

class Solution {
    public boolean isBalanced(TreeNode root) {
         if(root==null) {
          return true;
      }else {
       Stack<TreeNode> data=new Stack<TreeNode>();
       data.add(root);
       while(!data.empty()) {
           TreeNode temp=data.pop();
           int rinum=0,lenum=0;
           if(temp.right!=null) {
               data.push(temp.right);
               List<TreeNode> rightlist=new ArrayList<TreeNode>();
               rightlist.add(temp.right);
               rinum=getTree(rightlist);

           }
           if(temp.left!=null) {
               data.push(temp.left);
               List<TreeNode> leftlist=new ArrayList<TreeNode>();
               leftlist.add(temp.left);
               lenum=getTree(leftlist);
           }
           
           if(Math.abs(lenum-rinum)>1) {
               return false;
           }          
       }
       return true;
      }
    }
    public int getTree(List<TreeNode> list) {
        if(list.size()==0) {
            return 0;
        }
        
        List<TreeNode> dataList=new ArrayList<TreeNode>();
        for(int i=0;i<list.size();i++) {
            TreeNode tempNode=list.get(i);
            if(tempNode.left!=null) {
                dataList.add(tempNode.left);
            }
            if(tempNode.right!=null) {
                dataList.add(tempNode.right);
            }
        }
        return getTree(dataList)+1;
        
    }
}