//二叉树的基本操作#include <iostream.h>typedef struct node //定义结点{ char data;struct node *lchild, *rchild;} BinTNode;typedef BinTNode *BinTree; //定义二叉树void CreateBinTree(BinTree &T); //先序创建二叉树void PreOrder(BinTree T); //先序遍历二叉树void InOrder(BinTree T); //中序遍历二叉树void PostOrder(BinTree T); //后序遍历二叉树int onechild(BinTree T); //求度为1的结点的个数int leafs(BinTree T); //求叶子结点的个数int twochild(BinTree T); //度为2的结点的个数void translevel(BinTree b); //层序遍历二叉树void main(){int n;BinTree T;char ch1,ch2;cout<<"欢迎进入二叉树测试程序的基本操作"<<endl;cout<<"--------------请选择------------"<<endl;ch1='y';while(ch1=='y'||ch1=='Y'){cout<<"1---------建立二叉树\n";cout<<"2---------先序遍历\n";cout<<"3---------中序遍历\n";cout<<"4---------后序遍历\n";cout<<"5---------单孩子结点数\n";cout<<"6---------双孩子结点数\n";cout<<"7---------叶子结点数\n";cout<<"8---------层序遍历\n";cout<<"X---------退出\n";cin>>ch2;switch(ch2){case '1':cout<<"请输入按先序建立二叉树的结点序列：\n";CreateBinTree(T);cout<<endl;break;case '2':cout<<"二叉树的先序遍历序列：\n";PreOrder(T);cout<<endl;break;case '3':cout<<"二叉树的中序遍历序列：\n";InOrder(T);cout<<endl;break;case '4':cout<<"二叉树的后序遍历序列：\n";PostOrder(T);cout<<endl;break;case '5':cout<<"二叉树的单孩子结点数：\n";n=onechild(T);cout<<n<<endl;cout<<endl;break;case '6':cout<<"二叉树的双孩子结点数：\n";n=twochild(T);cout<<n<<endl;cout<<endl;break;case '7':cout<<"二叉树的叶子结点数：\n";n=leafs(T);cout<<n<<endl;cout<<endl;break;case '8':cout<<"二叉树的层序遍历序列：\n";translevel(T);cout<<endl;break;case 'x':case 'X':ch1='x';break;}}}void CreateBinTree(BinTree &T){char ch;cin>>ch;if(ch=='0') T=NULL;else{T=(BinTNode *)new BinTNode;T->data=ch;CreateBinTree(T->lchild );CreateBinTree(T->rchild );}}void InOrder(BinTree T){if(T){InOrder(T->lchild );cout<<T->data;InOrder(T->rchild );}}void PostOrder(BinTree T){if(T){PostOrder(T->lchild );PostOrder(T->rchild );cout<<T->data;}}void PreOrder(BinTree T){if(T){cout<<T->data;PreOrder(T->lchild );PreOrder(T->rchild );}}//层序遍历二叉树//采用一个队列q，先将二叉树的根结点入队列，然后退队列，输出该结点，若它有左子树，便将左子树根结点入队列，若它有右子树，便将右子树根结点入队列，如此直到队列空为止。

//因为队列的特点是先进先出，从而达到按层序遍历的目的。

#define MAXLEN 100void translevel(BinTree b){struct node{BinTree vec[MAXLEN];int f, r;}q; //定义队列q，f 表示队头指针，r队尾指针q.f=0; //置队列为空队列q.r=0;if(b!=NULL) cout<< b->data<<" ";q.vec[q.r]=b; //结点指针进入队列q.r=q.r+1; //队尾指针后移while(q.f<q.r) //队列不为空{b=q.vec[q.f]; //队头出队列q.f=q.f+1;if(b->lchild!=NULL) //输出左孩子，并入队列{cout<< b->lchild->data<<" ";q.vec[q.r]=b->lchild;q.r=q.r+1;}if(b->rchild!=NULL) //输出右孩子，并入队列{cout<< b->rchild->data<<" ";q.vec[q.r]=b->rchild;q.r=q.r+1;}}}int onechild(BinTree T)//求度为1的结点的个数{if(T==NULL) return 0;else if(T->lchild ==NULL && T->rchild!=NULL||T->lchild!=NULL && T->rchild==NULL)return (onechild(T->lchild)+onechild(T->rchild)+1);elsereturn (onechild(T->lchild)+onechild(T->rchild));}int leafs(BinTree T){int num1,num2;if(T==NULL) return 0;else if(T->lchild==NULL &&T->rchild ==NULL) return 1;else{num1=leafs(T->lchild );num2=leafs(T->rchild );return num1+num2;}}int twochild(BinTree T){int num0=0,num1,num2;if(T==NULL) return 0;else if(T->lchild!=NULL && T->rchild!=NULL) num0=1;num1=twochild(T->lchild);num2=twochild(T->rchild);return num0+num1+num2;}。