LeetCode_E_101
class Solution101 {
public boolean isSymmetric(TreeNode root) {
if(root == null) return true;
if(root.equals("")) return true;
if(root.equals(" ")) return true;
return isEquals(root.left, root.right);
}
public boolean isEquals(TreeNode rootLeft, TreeNode rootRight){
if(rootLeft == null && rootRight == null) return true;
if(rootLeft == null || rootRight == null) return false;
return (rootLeft.val == rootRight.val) && isEquals(rootLeft.left, rootRight.right) && isEquals(rootRight.left, rootLeft.right);
}
}
class TreeNode {
int val;
TreeNode left;
TreeNode right;
TreeNode(int x) { val = x; }
}