226. Invert Binary Tree
Total Accepted: 60170 Total Submissions: 140987 Difficulty: Easy
Invert a binary tree.
4
/ \
2 7
/ \ / \
1 3 6 9
to
4
/ \
7 2
/ \ / \
9 6 3 1
Trivia:如题,将一个二叉树翻转:
public class Solution {
public TreeNode invertTree(TreeNode root) {
/*if(root!=null){
TreeNode temp=root.left;
temp.val=root.left.val;
root.left=root.right;
root.left.val=root.right.val;
root.right=temp;
root.right.val=temp.val;
}
return root;
*/
if(root==null) return root;
TreeNode temp;
temp=root.left;
root.left=invertTree(root.right);
root.right=invertTree(temp);
return root;
}
}
注释部分提交后会出现空指针错误。使用了递归的思想,有较强的借鉴意义!