数据结构之二叉树的各种运算

#include <iostream>
#include <malloc.h>
#define MaxSize 100
using namespace std;
typedef struct node
{
    char data;
    struct node *lchild;
    struct node *rchild;
} BTNode;
void CreateBTNode(BTNode *&b,char *str)
{
    BTNode *St[MaxSize],*p=NULL;
    int top=-1,k,j=0;
    char ch;
    b=NULL;
    ch=str[j];
    while (ch!='\0')
    {
        switch(ch)
        {
        case '(':
            top++;
            St[top]=p;
            k=1;
            break;
        case ')':
            top--;
            break;
        case ',':
            k=2;
            break;
        default:
            p=(BTNode *)malloc(sizeof(BTNode));
            p->data=ch;
            p->lchild=p->rchild=NULL;
            if (b==NULL)
                b=p;
            else
            {
                switch(k)
                {
                case 1:
                    St[top]->lchild=p;
                    break;
                case 2:
                    St[top]->rchild=p;
                    break;
                }
            }
        }
        j++;
        ch=str[j];
    }
}
BTNode * FindNode(BTNode *b,char x)
{
    BTNode *p;
    if (b==NULL)
    {
        return NULL;
    }
    else if (b->data==x)
    {
        return b;
    }
    else
    {
        p=FindNode(b->lchild,x);
        if (p!=NULL)
            return p;
        else
            return FindNode(b->rchild,x);
    }

}
BTNode *LchildNode(BTNode *p)
{
    return p->lchild;
}
BTNode *RchildNode(BTNode *p)
{
    return p->rchild;
}
int BTNodeHeight(BTNode *b)
{
    int lchildh,rchildh;
    if (b==NULL)
        return 0;
    else
    {
        lchildh=BTNodeHeight(b->lchild);
        rchildh=BTNodeHeight(b->rchild);
        return (lchildh>rchildh)?(lchildh+1):(rchildh+1);
    }
}
void DispBTNode(BTNode *b)
{
    if(b!=NULL)
    {
        cout<<b->data;
        if (b->lchild!=NULL||b->rchild!=NULL)
        {
            cout<<"(";
            DispBTNode(b->lchild);
            if (b->rchild!=NULL)
                cout<<",";
            DispBTNode(b->rchild);
            cout<<")";
        }
    }
}

int BTWidth(BTNode *b)  //求二叉树b的宽度
{
    struct
    {
        int lno;		//节点的层次编号
        BTNode *p;		//节点指针
    } Qu[MaxSize];		//定义顺序非循环队列
    int front,rear;							//定义队首和队尾指针
    int lnum,max,i,n;
    front=rear=0;							//置队列为空队
    if (b!=NULL)
    {
        rear++;
        Qu[rear].p=b;						//根节点指针入队
        Qu[rear].lno=1;						//根节点的层次编号为1
        while (rear!=front)					//队列不为空
        {
            front++;
            b=Qu[front].p;					//队头出队
            lnum=Qu[front].lno;
            if (b->lchild!=NULL)			//左孩子入队
            {
                rear++;
                Qu[rear].p=b->lchild;
                Qu[rear].lno=lnum+1;
            }
            if (b->rchild!=NULL)			//右孩子入队
            {
                rear++;
                Qu[rear].p=b->rchild;
                Qu[rear].lno=lnum+1;
            }
        }
        max=0;
        lnum=1;
        i=1;
        while (i<=rear)
        {
            n=0;
            while (i<=rear && Qu[i].lno==lnum)
            {
                n++;
                i++;
            }
            lnum=Qu[i].lno;
            if (n>max) max=n;
        }
        return max;
    }
    else
        return 0;
}
int Nodes(BTNode *b)
{
    int num1,num2;
    if (b==NULL)
        return 0;
    else if (b->lchild==NULL && b->rchild==NULL)
        return 1;
    else
    {
        num1=Nodes(b->lchild);
        num2=Nodes(b->rchild);
        return (num1+num2+1);
    }
}
int LeafNodes(BTNode *b)
{
    int num1,num2;
    if (b==NULL)
        return 0;
    else if (b->lchild==NULL && b->rchild==NULL)
        return 1;
    else
    {
        num1=LeafNodes(b->lchild);
        num2=LeafNodes(b->rchild);
        return (num1+num2);
    }
}
void DestroyBTNode(BTNode *&b)
{
    if (b!=NULL)
    {
        DestroyBTNode(b->lchild);
        DestroyBTNode(b->rchild);
        free(b);
    }
}

int main()
{
    BTNode *b,*p,*lp,*rp;
    CreateBTNode(b,"A(B(D,E(H(J,K(L,M(,N))))),C(F,G(,I)))");
    cout<<"(1)输出二叉树：";
    DispBTNode(b);
    cout<<endl;
    cout<<"(2)输出H节点的左右孩子节点值:"<<endl;
    p=FindNode(b,'H');
    if (p!=NULL)
    {
        lp=LchildNode(p);
        if (lp!=NULL)
            cout<<"左孩子为："<<lp->data<<endl;
        else
            cout<<"无左孩子"<<endl;
        rp=RchildNode(p);
        if (rp!=NULL)
            cout<<"右孩子为："<<rp->data<<endl;
        else
            cout<<"无左孩子"<<endl;
    }
    cout<<"(3)输出二叉树b的深度："<<BTNodeHeight(b)<<endl;
    cout<<"(4)输出二叉树b的宽度："<<BTWidth(b)<<endl;
    cout<<"(5)输出二叉树b的节点个数："<<Nodes(b)<<endl;
    cout<<"(6)输出二叉树b的叶子节点个数："<<LeafNodes(b)<<endl;
    cout<<"释放二叉树.";
    DestroyBTNode(b);
    return 0;
}