Invert a binary tree.
Example:
Input:
4 / 2 7 / \ / 1 3 6 9
Output:
4 / 7 2 / \ / 9 6 3 1
public TreeNode invertTree(TreeNode root) {//树 递归 my
if (null!=root){
TreeNode left = invertTree(root.left);
TreeNode right = invertTree(root.right);
root.left=right;
root.right=left;
}
return root;
}
非递归的方法
public TreeNode invertTree(TreeNode root) {
if (root == null) return null;
Queue<TreeNode> queue = new LinkedList<TreeNode>();
queue.add(root);
while (!queue.isEmpty()) {
TreeNode current = queue.poll();
TreeNode temp = current.left;
current.left = current.right;
current.right = temp;
if (current.left != null) queue.add(current.left);
if (current.right != null) queue.add(current.right);
}
return root;
}
LeetCode-226.Invert Binary Tree
原文：https://www.cnblogs.com/zhacai/p/10431018.html