[数据结构与算法]创建二叉树并镜像

#include<stdio.h>
#include<queue>

template <class T>
struct TreeNode
{
	T data;
	TreeNode<T>* left;
	TreeNode<T>* right;
};



void mirror(TreeNode<int>* root)
{
	if (root == nullptr)
		return;
	std::queue<TreeNode<int>*> q;
	q.push(root);
	while (!q.empty())
	{
		TreeNode<int>* r = q.front();
		TreeNode<int>* T = r->right;
		r->right = r->left;
		r->left = T;
		if (r->right)
			q.push(r->right);
		if (r->left)
			q.push(r->left);
		q.pop();
	}


}


TreeNode<int>* BuildTree(int n)
{
	TreeNode<int>** arr = new TreeNode<int>*[n];
	for (int i = 0; i < n; i++)
	{
		TreeNode<int>* root = new TreeNode<int>;
		root->data = i;
		root->left = nullptr;
		root->right = nullptr;
		arr[i] = root;
	}
	for (int j = 0; j < n; j++)
	{
		if(2*j+1<n)
		arr[j]->left = arr[2 * j + 1];
		if(2*j+2<n)
		arr[j]->right = arr[2 * j + 2];
	}
	return arr[0];
}


TreeNode<int>* BuildTree2(int i, int n)
{
	if (i >= n)
		return nullptr;
	TreeNode<int>* root = new TreeNode<int>;
	root->left = BuildTree2(2 * i + 1, n);
	root->right = BuildTree2(2*i+2,n);
	root->data = i;
	return root;
}

int main()
{	
	TreeNode<int>* root = BuildTree(10);
	TreeNode<int>* root2 = BuildTree2(0,10);
	mirror(root);
	return 0;
}