二叉搜尋樹C++實現

標籤：

  1 template<typename Element>  2 class BinarySearchTree  3 {  4     public:  5         BinarySearchTree():root(NULL){}  6         BinarySearchTree(const BinarySearchTree& bst):root(NULL)  7         {  8             operator=(bst);  9         } 10         virtual ~BinarySearchTree() 11         { clear(root); } 12  13         void insert(const Element& e) 14         { insert(root, e); } 15         void remove(const Element& e) 16         { remove(root, e); } 17         bool contains(const Element& e) const 18         { return contains(root, e); } 19         const Element& findMin() const 20         { return findMin(root); } 21         const Element& findMax() const 22         { return findMax(root); } 23         bool isEmpty() const 24         { return root==NULL; } 25         void clear() 26         { clear(root); } 27  28         const BinarySearchTree& operator=(const BinarySearchTree& bst) 29         { 30             if(this!=&bst) 31             { 32                 clear(); 33                 root = clone(bst.root); 34             } 35             return *this; 36         } 37  38     private: 39         struct BSTNode 40         { 41             Element element; 42             BSTNode *left; 43             BSTNode *right; 44             BSTNode(const Element& e, BSTNode *lt, BSTNode *rt): 45                 element(e), left(lt), right(rt){} 46         }; 47         BSTNode *root; 48  49         BSTNode* clone(BSTNode * t) 50         { 51             if(t!=NULL) 52             { 53                 return new BSTNode(t->element, clone(t->left), clone(t->right)); 54             } 55             return NULL; 56         } 57         void clear(BSTNode * &t) 58         { 59             if(t!=NULL) 60             { 61                 clear(t->left); 62                 clear(t->right); 63                 delete t; 64             } 65             t = NULL; 66         } 67         void insert(BSTNode * &t, const Element& e) 68         { 69             if(t!=NULL) 70             { 71                 if(e<t->element) 72                 { 73                     insert(t->left, e); 74                 } 75                 else if(e>t->element) 76                 { 77                     insert(t->right, e); 78                 } 79                 else 80                 { 81                 } 82             } 83             else 84             { 85                 t = new BSTNode(e, NULL, NULL); 86             } 87         } 88         void remove(BSTNode * &t, const Element& e) 89         { 90             if(t!=NULL) 91             { 92                 if(e<t->element) 93                 { 94                     remove(t->left, e); 95                 } 96                 else if(e>t->element) 97                 { 98                     remove(t->right, e); 99                 }100                 else if(t->left!=NULL&&t->right!=NULL)101                 {102                     t->element = findMin(t->right);103                     remove(t->right, t->element);104                 }105                 else106                 {107                     BSTNode *tmp = t;108                     t = t->left!=NULL?t->left:t->right;109                     delete tmp;110                 }111             }112         }113         bool contains(BSTNode * t, const Element& e) const114         {115             if(t!=NULL)116             {117                 if(e<t->element)118                 {119                     return contains(t->left, e);120                 }121                 else if(e>t->element)122                 {123                     return contains(t->right, e);124                 }125                 else126                 {127                     return true;128                 }129             }130             else131             {132                 return false;133             }134         }135         const Element& findMin(BSTNode* t) const136         {137             return t->left!=NULL?findMin(t->left):t->element;138         }139         const Element& findMax(BSTNode* t) const140         {141             return t->right!=NULL?findMax(t->right):t->element;142         }143 };

 

二叉搜尋樹C++實現