创建二叉树

/*
* LeetCode--Same Tree
* date 2014/5/13
* state AC
*/
#include <iostream>

using namespace std;

/**
 * Definition for binary tree
 */
struct TreeNode
{
    char val;
    TreeNode *left;
    TreeNode *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};

class Solution {
public:
    bool isSameTree(TreeNode *p, TreeNode *q) {
        /*
        if(p->val==q->val && isSameTree(p->left,q->left) && isSameTree(p->right,q->right))
        return true;
        else return false;
        */
        //return isSameTree(p->left,q->left);
        //return isSameTree(p->right,q->right);
        if(p==NULL && q==NULL)return true;//两者都是NULL
        if(p!=NULL && q!=NULL && p->val==q->val//两者结点数据相等
           && isSameTree(p->left,q->left) //且左子树相同
           && isSameTree(p->right,q->right))//且右子树相同
            return true;
        else return false;
    }
};

//前序遍历建树
void createBinTree(TreeNode*& T)//指针引用
{
    //TreeNode* root;
    char temp;
    cin>>temp;
    if(temp=='#')T=NULL;
    else
    {
        //if()
        T=new TreeNode(temp);
        if(!T)return;
        createBinTree(T->left);
        createBinTree(T->right);
    }
}

//前序遍历树
void preOrder(TreeNode* root)
{
    if(root!=NULL)
    {
        cout<<root->val<<" ";
        preOrder(root->left);
        preOrder(root->right);
    }
}
/*
void CreateBiTree(TreeNode*& t)//必须用&
{
     char ch;
     cin>>ch;
     if(ch=='#')
         t=NULL;
     else
     {
         t=new TreeNode(ch);
         if(!t)
             return;
         //t->val=ch;
         CreateBiTree(t->left);
         CreateBiTree(t->right);
     }
 }

//先序遍历
void PreOrderTraverse(TreeNode* t)
{
    if(t)
    {
        cout<<t->val<<" ";
        PreOrderTraverse(t->left);
        PreOrderTraverse(t->right);
    }

}
*/

TreeNode* create()
{
    char ch;
    cin>>ch;
    TreeNode* root;
    if(ch=='#')
        return NULL;
    else
    {
        root=new TreeNode(ch);
        root->left=create();
        root->right=create();
        return root;
    }

}
int main()
{
    //cout << "Hello world!" << endl;
    TreeNode* t=NULL;
    //createBinTree(t);
    t=create();
    preOrder(t);
    //CreateBiTree(t);

    return 0;
}