【leetcode】226-invert-binary-tree

problem

226-invert-binary-tree

code

solution1-DFS

/**
 * 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==NULL) return NULL;
        TreeNode* tmp = root->left;
        root->left = invertTree(root->right);
        root->right = invertTree(tmp);
        return root;
    }
};

solution2-BFS

/**
 * 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==NULL) return NULL;
        queue<TreeNode*> myqueue;
        myqueue.push(root);
        while(!myqueue.empty())
        {
            TreeNode* node = myqueue.front();
            myqueue.pop();
            TreeNode* tmp = node->left;
            node->left = node->right;
            node->right = tmp;
            if(node->right)myqueue.push(node->right);
            if(node->left) myqueue.push(node->left);
 
        }
        return root;
    }
};

参考

1. Leetcode_226-invert-binary-tree;

完