剑指offer 平衡二叉树

public boolean IsBalanced_Solution(TreeNode root) {
if (root == null) {
return true;
}
int left = TreeDepth(root.left);
int right = TreeDepth(root.right);
int dis = left - right;
if (dis > 1 || dis < -1) {
return false;
}
return IsBalanced_Solution(root.left) && IsBalanced_Solution(root.right);
}

/**
* 只有左子树,depth=左子树深度+1
* 只有右子树,depth=右子树深度+1
* 有左右子树,depth=max(左子树深度,右子树深度)+1
*
* @param pRoot
* @return
*/
public int TreeDepth(TreeNode pRoot) {
if (pRoot == null) {
return 0;
}
int left = TreeDepth(pRoot.left);
int right = TreeDepth(pRoot.right);
return (left > right) ? (left + 1) : (right + 1);
}