平衡二叉树

输入一棵二叉树，判断该二叉树是否是平衡二叉树。

package balancedTree;

class TreeNode{
TreeNode left;
TreeNode right;
int val;
}

public class Solution {

public boolean IsBalanced_Solution(TreeNode root) {
if(root==null){
return true;
}
if(Math.abs(treeDepth(root.left)-treeDepth(root.right))<=1){
return true;
}else{
return false;
}
}

public int treeDepth(TreeNode root){
if(root==null){
return 0;
}
int i=treeDepth(root.left);
int j=treeDepth(root.right);
int depth=(i>j)?(i+1):(j+1);
return depth;
}

}