用循环的方法实现二叉树的镜像

程序中包含了递归方法 和循环方法

#include <iostream>
#include <queue>
using namespace std;
struct tree
{
	int value;
	tree *left;
	tree *right;
};
tree *create()
{
	int n;
	cin>>n;
	if (n == 0)
	{
		return NULL;
	}
	else
	{
		tree *root = new tree;
		root->value = n;
		root->left = create();
		root->right = create();
		return root;
	}

}
void pre(tree *root)
{
	if (root == NULL)
	{
		return;
	}
	else
	{
		cout<<root->value<<" ";
		pre(root->left);
		pre(root->right);
	}
}
void mirror_digui(tree *root)
{
	if (root == NULL || (root->left==NULL && root->right==NULL))
	{
		return ;
	}
	tree *temp = root->left;
	root->left = root->right;
	root->right = temp;
	if (root->left != NULL)
	{
		mirror_digui(root->left);
	}
	if (root->right != NULL)
	{
		mirror_digui(root->right);
	}

}
void mirror_xunhuan(tree *root)
{
	if (root == NULL || (root->left==NULL && root->right==NULL))
	{
		return ;
	}
	queue<tree *> q;
	q.push(root);
	while(!q.empty())
	{
		tree *newroot = q.front();
		q.pop();
		tree *temp = newroot->left;
		newroot->left = newroot->right;
		newroot->right = temp;
		if (newroot->left!=NULL)
		{
			q.push(newroot->left);
		}
		if (newroot->right!=NULL)
		{
			q.push(newroot->right);
		}

	}
}
int main()
{
	tree *root = create();
	pre(root);
	cout<<endl;
	mirror_xunhuan(root);
	pre(root);

	return 0;

}

用循环的方法实现二叉树的镜像