数据结构-二叉树:C++模板类递归实现与非递归实现

C++模板类递归实现与非递归实现二叉树遍历

实现的功能: 

1.存储，2.前序遍历，3.中序遍历，4.后序遍历，5.层序遍历。

递归实现二叉树代码：

//二叉树-二叉链表-递归********************************************************************//输入示范：//        A                             A//      B   C    :AB##C##            B     C     :ABD##E##CF##G##//                                  D  E  F  G   #include <iostream>using namespace std;#define NODE_NUM 1000template <class DataType>struct BiNode{DataType data;BiNode<DataType> *lchild, *rchild;};template <class DataType>class BiTree{public:BiTree(){ root = Create(root); }~BiTree(){ Release(root); }void PreOrder(){ PreOrder(root); }  //前序遍历void InOrder(){ InOrder(root); }    //中序遍历void PostOrder(){ PostOrder(root); }//后序遍历void LevelOrder();                  //层次遍历  private:BiNode <DataType> *root;BiNode <DataType> *Q_tree[NODE_NUM];int tree_front, tree_rear;BiNode<DataType> *Create(BiNode<DataType>* bt);void Release(BiNode<DataType>* bt);void PreOrder(BiNode<DataType>* bt); void InOrder(BiNode<DataType>* bt);  void PostOrder(BiNode<DataType>* bt);};template <class DataType>void BiTree<DataType>::PreOrder(BiNode<DataType>* bt)//前序遍历{if (bt != NULL){cout << bt->data<<" ";PreOrder(bt->lchild);PreOrder(bt->rchild);}}template <class DataType>void BiTree<DataType>::InOrder(BiNode<DataType>* bt)//中序遍历{if (bt == NULL)return;else{InOrder(bt->lchild);cout << bt->data << " ";InOrder(bt->rchild);}}template <class DataType>void BiTree<DataType>::PostOrder(BiNode<DataType>* bt)//后序遍历{if (bt == NULL)return;else{PostOrder(bt->lchild);PostOrder(bt->rchild);cout << bt->data << " ";}}template <class DataType>void BiTree<DataType>::LevelOrder()//层序遍历{BiNode<DataType> *q_node = (BiNode<DataType> *)malloc(sizeof(BiNode<DataType>));BiNode<DataType> *qq = (BiNode<DataType> *)malloc(sizeof(BiNode<DataType>));tree_front = tree_rear = -1;if (root == NULL)return;Q_tree[++tree_rear] = root;//数组Q_tree中Q[0]存整个二叉树，Q[1]、Q[2]存第二层的子树，Q[3]、Q[4]存第三层子树，以此类推while (tree_front != tree_rear){q_node = Q_tree[++tree_front];cout << q_node->data << " ";//按层显示该位置上子树的根节点，即层序遍历if (q_node->lchild != NULL)Q_tree[++tree_rear] = q_node->lchild;if (q_node->rchild != NULL)Q_tree[++tree_rear] = q_node->rchild;}}template <class DataType>BiNode<DataType>* BiTree<DataType>::Create(BiNode<DataType>* bt)//前序遍历生成二叉链表，如A的两个子节点BC，则输入应为AB##C##{DataType ch_tree;cout << "请输入节点:";cin >> ch_tree;if (ch_tree == '#')bt = NULL;else{bt = new BiNode<DataType>;bt->data = ch_tree;bt->lchild = Create(bt->lchild);bt->rchild = Create(bt->rchild);}return bt;}template <class DataType>void BiTree<DataType>::Release(BiNode<DataType>* bt)//释放内存{if (bt != NULL){Release(bt->lchild);Release(bt->rchild);delete bt;}}//主函数int main(){BiTree<char> my_tree;cout << "前序遍历:";my_tree.PreOrder();cout << endl;cout << "中序遍历:";my_tree.InOrder();cout << endl;cout << "后序遍历:";my_tree.PostOrder();cout << endl;cout << "层序遍历:";my_tree.LevelOrder();cout << endl;return 0;}

非递归实现二叉树代码：

//二叉树--非递归实现********************************************************************//输入示范：//        A                             A//      B   C    :AB##C##            B     C     :ABD##E##CF##G##//                                  D  E  F  G   #include <iostream>#include <queue>#include<stack> using namespace std;template <class DataType>struct BiNode{DataType data;BiNode<DataType> *lchild, *rchild;};template <class DataType>class BiTree{public:BiTree(){ root = Create(root); }      //生成二叉树~BiTree(){ Release(root); }           //释放内存void PreOrder(){ PreOrder(root); }    //前序遍历void InOrder(){ InOrder(root); }      //中序遍历void PostOrder(){ PostOrder(root); }  //后序遍历void LevelOrder(){ LevelOrder(root); }//层次遍历 private:BiNode <DataType> *root;BiNode<DataType> *Create(BiNode<DataType>* bt);void Release(BiNode<DataType>* bt);void PreOrder(BiNode<DataType>* bt);void InOrder(BiNode<DataType>* bt);void PostOrder(BiNode<DataType>* bt);void LevelOrder(BiNode<DataType>* bt);};template <class DataType>void BiTree<DataType>::PreOrder(BiNode<DataType>* bt)//前序遍历{stack< BiNode<DataType> *> stack;while (bt != NULL || !stack.empty()){while (bt != NULL){cout << bt->data << " ";stack.push(bt);bt = bt->lchild;}if (!stack.empty()){bt = stack.top();stack.pop();bt = bt->rchild;}}}template <class DataType>void BiTree<DataType>::InOrder(BiNode<DataType>* bt)//中序遍历{stack< BiNode<DataType> *> stack;while (bt != NULL || !stack.empty()){while (bt != NULL){stack.push(bt);bt = bt->lchild;}if (!stack.empty()){bt = stack.top();stack.pop();cout << bt->data << " ";bt = bt->rchild;}}}template<class DataType>void BiTree<DataType>::PostOrder(BiNode<DataType>* bt)//后序遍历{//要保证根结点在左孩子和右孩子访问之后才能访问，  //因此对于任一结点P，先将其入栈。如果P不存在左孩子和右孩子，则可以直接访问它；  //或者P存在左孩子或者右孩子，但是其左孩子和右孩子都已被访问过了，则同样可以直接访问该结点。  //若非上述两种情况，则将P的右孩子和左孩子依次入栈，这样就保证了每次取栈顶元素的时候，  //左孩子在右孩子前面被访问，左孩子和右孩子都在根结点前面被访问。  if (bt == NULL)return;stack<BiNode<DataType>*> stack;stack.push(bt);BiNode<DataType>* pre = NULL;BiNode<DataType>* cur;while (!stack.empty()){cur = stack.top();if (cur->lchild == NULL && cur->rchild == NULL ||(pre != NULL) && (pre == cur->lchild || pre == cur->rchild))//上一次访问的是当前节点的左子树  {cout << cur->data << " ";stack.pop();pre = cur;}else{if (cur->rchild)stack.push(cur->rchild);if (cur->lchild)stack.push(cur->lchild);}}}template<class DataType>void BiTree<DataType>::LevelOrder(BiNode<DataType>* bt)//层序遍历{//层次遍历需要queue来实现，思路：  //@1初始化queue  //  if root为空 返回  //@2 push(root)  //@3 while(queue不为空)  //      s <-- queue.front()  //      queue.pop()  //      输入s.data  //      if(s的左子树不空)  //          s的左子树入队  //      if(s的右子树不空)  //          s的右子树入队  queue<BiNode<DataType>*> queue_q;BiNode<DataType>* tree_s = bt;if (tree_s == NULL)return;queue_q.push(tree_s);while (!queue_q.empty()){tree_s = queue_q.front();queue_q.pop();cout << tree_s->data << " ";if (tree_s->lchild)queue_q.push(tree_s->lchild);if (tree_s->rchild)queue_q.push(tree_s->rchild);}}template <class DataType>BiNode<DataType>* BiTree<DataType>::Create(BiNode<DataType>* bt)//前序遍历生成二叉链表，如A的两个子节点BC，则输入应为AB##C##{DataType ch_tree;cout << "请输入节点:";cin >> ch_tree;if (ch_tree == '#')bt = NULL;else{bt = new BiNode<DataType>;bt->data = ch_tree;bt->lchild = Create(bt->lchild);bt->rchild = Create(bt->rchild);}return bt;}template <class DataType>void BiTree<DataType>::Release(BiNode<DataType>* bt)//释放内存{if (bt != NULL){Release(bt->lchild);Release(bt->rchild);delete bt;}}//主函数int main(){BiTree<char> my_tree;cout << endl;cout << "前序遍历:";my_tree.PreOrder();cout << endl;cout << "中序遍历:";my_tree.InOrder();cout << endl;cout << "后序遍历:";my_tree.PostOrder();cout << endl;cout << "层序遍历:";my_tree.LevelOrder();cout << endl;return 0;}

参考博客：

http://blog.csdn.net/zhembrace/article/details/52974139