Invert a binary tree.
4 / \ 2 7 / \ / \ 1 3 6 9to
4 / \ 7 2 / \ / \ 9 6 3 1
思路:这个很简单,判断root是否为空,不为空则将左右子节点交换,然后递归进行左右子节点
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public TreeNode invertTree(TreeNode root) {
if(root==null){
return null;
}else{
TreeNode temp=root.left;
root.left=root.right;
root.right=temp;
invertTree(root.left);
invertTree(root.right);
return root;
}
}
}