二叉树--旋转二叉树

226. Invert Binary Tree

Invert a binary tree.

Example:

Input:

4 / \ 2 7 / \ / \ 1 3 6 9

Output:

4 / \ 7 2 / \ / \ 9 6 3 1

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    TreeNode* invertTree(TreeNode* root) {
        if(root == nullptr){
            return root;
        }
        queue<TreeNode*> q;
        q.push(root);
        while(!q.empty()){
            TreeNode* tmp = q.front();
            q.pop();
            TreeNode* n = tmp->left;
            tmp->left = tmp->right;
            tmp->right = n;
            if(tmp->left){
                q.push(tmp->left);
            }
            if(tmp->right){
                q.push(tmp->right);
            }
        }
        return root;
    }
};