二叉树

二叉树的各种遍历

#include <stdio.h>#include <malloc.h>#include <stack>#include <queue>#include "stack.h"using std::stack;using std::queue;typedef struct _node{int value;_node* pLChild;_node* pRChild;int visited; //用于树的后续非递归排序}Node,*Tree;//创建树void CreateTree(Tree* tree);//非递归前序遍历void PreOrder(Tree tree);//非递归中序遍历void InOrder(Tree tree);//非递归后序遍历void PostOrder(Tree tree);//按层遍历void LevelOrder(Tree tree);//递归前序遍历void PreOrderNoRec(Tree tree);//递归中序遍历void InOrderNoRec(Tree tree);//递归后序遍历void PostOrderNoRec(Tree tree);//获得树的深度int GetDepth(Tree tree);int main(){Tree tree;CreateTree(&tree);printf("%d ",GetDepth(tree));return 0;}void CreateTree(Tree* tree){int value;scanf("%d",&value);if(value == -1)*tree = NULL;else{*tree = (Tree)malloc(sizeof(Node));if(!(*tree))return;(*tree)->value = value;(*tree)->visited = 0;CreateTree(&(*tree)->pLChild);CreateTree(&(*tree)->pRChild);}}void PreOrder(Tree tree){if(tree == NULL)return ;else{printf("%d ",tree->value);PreOrder(tree->pLChild);PreOrder(tree->pRChild);}}void InOrder(Tree tree){ if(tree == NULL)return ;else{PreOrder(tree->pLChild);printf("%d ",tree->value);PreOrder(tree->pRChild);}}void PostOrder(Tree tree){if(tree == NULL)return ;else{PreOrder(tree->pLChild);PreOrder(tree->pRChild);printf("%d ",tree->value);}}void Destroy(Tree tree){}/*****************************************************************************首先需要一个栈，从树的根节点开始访问，然后访问左孩子并加入到栈中，然后继续向左访问，只到把所有的左边节点都访问玩，然后从栈里弹出一节点，继续上述访问。*****************************************************************************/void PreOrderNoRec(Tree tree){stack<Node*> sta;Node* pNode = tree;while(pNode || !sta.empty()){while(pNode){printf("%d ",pNode->value);sta.push(pNode);pNode = pNode->pLChild;}if(!sta.empty()){pNode = sta.top();sta.pop();pNode = pNode->pRChild;}}}void InOrderNoRec(Tree tree){stack<Node*> sta;Node* pNode = tree;while(pNode || !sta.empty()){while(pNode){sta.push(pNode);pNode = pNode->pLChild;}if(!sta.empty()){pNode = sta.top();sta.pop();printf("%d ",pNode->value);pNode = pNode->pRChild;}}}void PostOrderNoRec(Tree tree){Node* p,*q; p = tree; q = NULL;stack<Node*> sta;while(p||!sta.empty()) { if(p&&p->visited==0) { sta.push(p); p=p->pLChild; } else { p = sta.top(); sta.pop(); //右孩子不为空且没有访问 if(p->pRChild && p->pRChild->visited==0) { q=p; p=p->pRChild; //留着以后访问 sta.push(q); continue; } printf("%d",p->value); p->visited=1; } }}void LevelOrder(Tree tree){if(tree == NULL){printf("the tree is null........./n");return ;} queue<Node*> que;Node* pNode = tree;que.push(pNode);while(!que.empty()){pNode = que.front();que.pop();printf("%d ",pNode->value);if(pNode->pLChild)que.push(pNode->pLChild);if(pNode->pRChild)que.push(pNode->pRChild);}}int GetDepth(Tree tree){if(tree == NULL)return 0;int nl = GetDepth(tree->pLChild);int nr = GetDepth(tree->pRChild);if(nl > nr)return nl + 1;elsereturn nr + 1;}