​LeetCode刷题实战226：翻转二叉树

class Solution {
public:
    TreeNode* invertTree(TreeNode* root) 
    {
        if(root ==NULL) return root;
        TreeNode* node = invertTree(root->left);
        root->left = invertTree(root->right);
        root->right = node;
        return root;
    }
};

public class Solution {
    public TreeNode invertTree(TreeNode root) {
        Queue<TreeNode> q = new LinkedList<TreeNode>();
        if(root!=null) q.offer(root);
        while(!q.isEmpty()){
            TreeNode curr = q.poll();
            TreeNode tmp = curr.right;
            curr.right = curr.left;
            curr.left = tmp;
            if(curr.left!=null) q.offer(curr.left);
            if(curr.right!=null) q.offer(curr.right);
        }
        return root;
    }
}