二叉树的镜像

二叉树的镜像定义：源二叉树 
    	    8
    	   /  \
    	  6   10
    	 / \  / \
    	5  7 9 11
    	镜像二叉树
    	    8
    	   /  \
    	  10   6
    	 / \  / \
    	11 9 7  5
递归方法：

/*
struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
    TreeNode(int x) :
            val(x), left(NULL), right(NULL) {
    }
};*/
class Solution {
public:
    void Mirror(TreeNode *pRoot) {
        if(pRoot == NULL)
            return ;
        TreeNode * temp;
        if(pRoot->left || pRoot->right)
        {
            Mirror(pRoot->left);
            Mirror(pRoot->right);
            temp = pRoot->left;
            pRoot->left = pRoot->right;
            pRoot->right = temp;
        }
    }
};

非递归方法：即用栈实现

class Solution {
public:
    void Mirror(TreeNode *pRoot) {
        //非递归实现
        if(pRoot==NULL)
            return;
        stack<TreeNode*> stackNode;
        stackNode.push(pRoot);
        while(stackNode.size()){
            TreeNode* tree=stackNode.top();
            stackNode.pop();
            if(tree->left!=NULL || tree->right!=NULL){
                TreeNode *ptemp=tree->left;
                tree->left=tree->right;
                tree->right=ptemp;
            }
            if(tree->left)
                stackNode.push(tree->left);
            if(tree->right)
                stackNode.push(tree->right);
        }
    }
};