非递归前序遍历二叉树 运行不了

[henu_fyh]

#include<iostream>
using namespace std;
# include <stack>

struct trees
{
    trees *left;
    trees *rignt;
    char data;
 };


stack<trees> S;

void creat(trees *tree)
{
	char c;
	cout<<"please input the data : (expect '#')"<<endl;
	cin >> c;
	if(c=='#')
   {
        tree = NULL;
        return;
   }
	else
	{
		tree = new trees;
		tree->data=c;
		creat(tree->left);
		creat(tree->rignt);
	}
}

void show1(trees *tree) //前序
{
    trees temp;

	while (!S.empty()) S.pop();

	if(!tree)
	{
		cout<<"the tree is empty!"<<endl;
	}

	else
	{
		while(tree!=NULL||!S.empty())
        {
            while(tree!=NULL)
            {
                cout<< tree->data <<endl;           //不能正确的打印出来
                S.push(*tree);
                tree=tree->left;
            }
            temp = S.top();
            S.pop();
            tree=temp.rignt;
        }
	}

 }


int main()
{
	int leap;

	trees tree;

	while(cin>>leap)
	{
		switch(leap)
		{
			case 1: creat(T);break;
			case 2: show1(T);break;

		}
	}

	return 0;
}

[小灸舞]

传参应该是&tree吧？

#include<iostream>
using namespace std;
# include <stack>

struct trees
{
	trees *left;
	trees *rignt;
	char data;
};


stack<trees> S;

void creat(trees *tree)
{
	char c;
	cout << "please input the data : (expect '#')" << endl;
	cin >> c;
	if (c == '#')
	{
		tree = NULL;
		return;
	}
	else
	{
		tree = new trees;
		tree->data = c;
		creat(tree->left);
		creat(tree->rignt);
	}
}

void show1(trees *tree) //前序
{
	trees temp;

	while (!S.empty()) S.pop();

	if (!tree)
	{
		cout << "the tree is empty!" << endl;
	}

	else
	{
		while (tree != NULL || !S.empty())
		{
			while (tree != NULL)
			{
				cout << tree->data << endl;           //不能正确的打印出来
				S.push(*tree);
				tree = tree->left;
			}
			temp = S.top();
			S.pop();
			tree = temp.rignt;
		}
	}

}


int main()
{
	int leap;

	trees tree;

	while (cin >> leap)
	{
		switch (leap)
		{
		case 1: creat(&tree); break;
		case 2: show1(&tree); break;

		}
	}

	return 0;
}

[paschen]

case 1: creat(T);break; case 2: show1(T);break; 上面这两句中T你未声明