1 数据结构的练习与巩固
  2 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
  3 #include<iostream>
  4 using namespace std;
  5 
  6 template <class T> 
  7 struct BTNode
  8 {                                               //二叉树结点类定义
  9        T data;                                  //数据域
 10     BTNode<T> *lChild, *rChild;
 11                                                 //左子女、右子女链域
 12     BTNode ()                                   //构造函数
 13        { 
 14                lChild = NULL;  
 15                rChild = NULL; 
 16        }
 17        
 18     BTNode (T& x, BTNode<T> *l = NULL, BTNode<T> *r = NULL)
 19        { 
 20             data = x;  
 21             lChild = l;  
 22             rChild = r; 
 23        }
 24 };
 25 
 26 //二叉树类定义
 27 template <class T> 
 28 class BT 
 29 {            
 30 public:
 31      BTNode<T> *root;          //二叉树的根指针
 32      T RefValue;               //数据输入停止标志
 33 public:
 34         
 35     BT () : root (NULL) {}                          //构造函数
 36     BT (T value) : RefValue(value), root(NULL) {}   //构造函数
 37  
 38     BTNode<T> *lChild (BTNode<T> *t)
 39        { return (t != NULL)?t->lChild : NULL; }     //返回左子女
 40     BTNode<T> *rChild (BTNode<T> *t)
 41        { return (t != NULL)?t->rChild : NULL; }     //返回右子女
 42                                                           
 43     bool IsEmpty() { return root == NULL; }         //判二叉树空否                                                          
 44     BTNode<T> * & getRoot () { return root; }       //取根
 45      
 46     void PreOrder (BTNode<T>*& subTree);            //前序遍历
 47     void InOrder  (BTNode<T>*& subTree);            //中序遍历
 48     void postOrder(BTNode<T>*& subTree);            //后序遍历
 49     
 50     void CreateBT(BTNode<T>* & subTree);
 51     void BSTinsert(BTNode<T> *&BT, int Key);
 52     
 53     void Size (BTNode<T> * &subTree,int &count);    //返回结点数
 54     
 55     void leaf (BTNode<T> * &subTree,int &count);    //返回叶子数
 56 };
 57 
 58 template<class T>
 59 void BT<T>::PreOrder(BTNode<T>* &subTree)
 60 {
 61     if (subTree != NULL)
 62     {
 63         cout << subTree->data <<' ';
 64         PreOrder(subTree->lChild);
 65         PreOrder(subTree->rChild);
 66     }
 67 }
 68 
 69 template<class T>
 70 void BT<T>::InOrder(BTNode<T>* &subTree)
 71 {
 72     if (subTree != NULL)
 73     {
 74         InOrder(subTree->lChild);
 75         cout << subTree->data <<' ';
 76         InOrder(subTree->rChild);
 77     }
 78 }
 79 
 80 template<class T>
 81 void BT<T>::postOrder(BTNode<T>*& subTree)
 82 {
 83     if (subTree != NULL)
 84     {
 85         postOrder(subTree->lChild);
 86         postOrder(subTree->rChild);
 87         cout << subTree->data <<' ';
 88     }
 89 }
 90 
 91 //前序创建二叉树
 92 template<class T>
 93 void BT<T>::CreateBT(BTNode<T>*&subTree)               //注意用引用接收指针  如果只传入指针 形参的指针指向改变 实参不会变
 94 {
 95     T ch;
 96     cin >> ch;
 97         if (ch == RefValue) subTree = NULL;
 98         else
 99         {
100             subTree = new BTNode<T>(ch);                    //有参构造函数 建立结点
101             CreateBT(subTree->lChild);                      //递归
102             CreateBT(subTree->rChild);
103         }
104 }
105 
106 template<class T>
107 void BT<T>::Size (BTNode<T> * &subTree,int &count)
108 {
109     if (subTree != NULL)
110     {
111         count++;
112         Size(subTree->lChild,count);
113         Size(subTree->rChild,count);
114     }
115     else
116     return;
117 }
118 
119 template<class T>
120 void BT<T>::leaf (BTNode<T> * &subTree,int &count)
121 {
122     if(subTree!=NULL)
123     {
124         if(subTree->lChild==NULL && subTree->rChild==NULL)
125         {
126             count++;
127             return;
128         }
129         else
130         {
131             leaf(subTree->lChild,count);
132             leaf(subTree->rChild,count);
133         }    
134     }
135 }
136 
137 int main()
138 {
139     int c1=0,c2=0;
140     BT<char> t('#');
141     t.CreateBT(t.getRoot());
142         cout<<"前序遍历"<<endl; 
143     t.PreOrder(t.getRoot());
144         cout<<endl<<"中序遍历"<<endl;
145     t.InOrder(t.getRoot());
146         cout<<endl<<"后序遍历"<<endl;
147     t.postOrder(t.getRoot());
148     t.Size(t.getRoot(),c1);
149         cout<<endl<<"结点总个数："<<c1<<endl;
150     t.leaf(t.getRoot(),c2);
151     cout<<"叶子结点总个数："<<c2<<endl;
152 }