本文共 1034 字，大约阅读时间需要 3 分钟。

返回类型为void，用return NULL是肯定不对的 

/** * 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;        }        swapNode(root);        return root;    }    void swapNode(TreeNode* root){        if (root->left == NULL && root->right == NULL){            return;        }else{            TreeNode* temp;            temp = root->left;            root->left = root->right;            root->right = temp;            if (root->left != NULL){                invertTree(root->left);            }            if (root->right != NULL){                invertTree(root->right);            }        }    }};

转载地址：http://wjpbb.baihongyu.com/