【剑指offer】二叉树的镜像

/*
struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
    TreeNode(int x) :
            val(x), left(NULL), right(NULL) {
    }
};*/
class Solution
{
public:
    void dfs(TreeNode *root)
    {
        //交换左右子树
        TreeNode *temp;
        temp=root->left;
        root->left=root->right;
        root->right=temp;

        //继续对其左右子树进行交换操作
        if(root->left!=NULL)
            dfs(root->left);
        if(root->right!=NULL)
            dfs(root->right);

        return ;
    }
    void Mirror(TreeNode *root)
    {
        if(root!=NULL)
            dfs(root);
    }
};