二叉树层次遍历算法的验证 - 全文

/*   
* 问题描述: 实现二叉树的层次遍历算法，并对用”A(B(D,E(H(J,K(L,M(,N))))),C(F,G(,I)))”创建的二叉树进行测试。  
* 输入描述:无需输入  
* 程序输出:实现各种算法的函数的测试结果  
*/    

 view plain copy
#include  
#include "btree.h"  
  
void LevelOrder(BTNode *b)  
{  
    BTNode *p;  
    //环形队列采用顺序队存储结构  
    BTNode *qu[MaxSize];    //定义环形队列,存放节点指针  
    int front,rear; //定义队头和队尾指针  
    front=rear=-1;      //置队列为空队列  
    rear++;  
    qu[rear]=b;     //根节点指针进入队列  
    while (front!=rear) //队列不为空  
    {  
        front=(front+1)%MaxSize;  
        p=qu[front];        //队头出队列(出队结点p)  
        printf("%c ",p->data);  //访问节点  
        if (p->lchild!=NULL)    //有左孩子时将其进队  
        {  
            rear=(rear+1)%MaxSize;  
            qu[rear]=p->lchild;  
        }  
        if (p->rchild!=NULL)    //有右孩子时将其进队  
        {  
            rear=(rear+1)%MaxSize;  
            qu[rear]=p->rchild;  
        }  
    }  
}  

  

int main()  
{  
    BTNode *b;  
    CreateBTNode(b,"A(B(D,E(H(J,K(L,M(,N))))),C(F,G(,I)))");  
    printf("二叉树b: ");  
    DispBTNode(b);  
    printf("\n");  
    printf("层次遍历序列:\n");  
    LevelOrder(b);  
    DestroyBTNode(b);  
    return 0;  
}  
 
[cpp] view plain copy
#ifndef BTREE_H_INCLUDED  
#define BTREE_H_INCLUDED  
  
#define MaxSize 100  
typedef char ElemType;  
typedef struct node  
{  
    ElemType data;              //数据元素  
    struct node *lchild;        //指向左孩子  
    struct node *rchild;        //指向右孩子  
} BTNode;  
void CreateBTNode(BTNode *&b,char *str);        //由str串创建二叉链  
BTNode *FindNode(BTNode *b,ElemType x);     //返回data域为x的节点指针  
BTNode *LchildNode(BTNode *p);  //返回*p节点的左孩子节点指针  
BTNode *RchildNode(BTNode *p);  //返回*p节点的右孩子节点指针  
int BTNodeDepth(BTNode *b); //求二叉树b的深度  
void DispBTNode(BTNode *b); //以括号表示法输出二叉树  
void DestroyBTNode(BTNode *&b);  //销毁二叉树  
  
#endif // BTREE_H_INCLUDED  
 
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#include  
#include  
#include "btree.h"  
  
void CreateBTNode(BTNode *&b,char *str)     //由str串创建二叉链  
{  
    BTNode *St[MaxSize],*p=NULL;  
    int top=-1,k,j=0;  
    char ch;  
    b=NULL;             //建立的二叉树初始时为空  
    ch=str[j];  
    while (ch!='\0')    //str未扫描完时循环  
    {  
        switch(ch)  
        {  
        case '(':  
            top++;  
            St[top]=p;  
            k=1;  
            break;      //为左节点  
        case ')':  
            top--;  
            break;  
        case ',':  
            k=2;  
            break;                          //为右节点  
        default:  
            p=(BTNode *)malloc(sizeof(BTNode));  
            p->data=ch;  
            p->lchild=p->rchild=NULL;  
            if (b==NULL)                    //p指向二叉树的根节点  
                b=p;  
            else                            //已建立二叉树根节点  
            {  
                switch(k)  
                {  
                case 1:  
                    St[top]->lchild=p;  
                    break;  
                case 2:  
                    St[top]->rchild=p;  
                    break;  
                }  
            }  
        }  
        j++;  
        ch=str[j];  
    }  
}  

BTNode *FindNode(BTNode *b,ElemType x)  //返回data域为x的节点指针  
{  
    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)   //返回*p节点的左孩子节点指针  
{  
    return p->lchild;  
}  
BTNode *RchildNode(BTNode *p)   //返回*p节点的右孩子节点指针  
{  
    return p->rchild;  
}  
int BTNodeDepth(BTNode *b)  //求二叉树b的深度  
{  
    int lchilddep,rchilddep;  
    if (b==NULL)  
        return(0);                          //空树的高度为0  
    else  
    {  
        lchilddep=BTNodeDepth(b->lchild);   //求左子树的高度为lchilddep  
        rchilddep=BTNodeDepth(b->rchild);   //求右子树的高度为rchilddep  
        return (lchilddep>rchilddep)? (lchilddep+1):(rchilddep+1);  
    }  
}  
void DispBTNode(BTNode *b)  //以括号表示法输出二叉树  
{  
    if (b!=NULL)  
    {  
        printf("%c",b->data);  
        if (b->lchild!=NULL || b->rchild!=NULL)  
        {  
            printf("(");  
            DispBTNode(b->lchild);  
            if (b->rchild!=NULL) printf(",");  
            DispBTNode(b->rchild);  
            printf(")");  
        }  
    }  
}  
void DestroyBTNode(BTNode *&b)   //销毁二叉树  
{  
    if (b!=NULL)  
    {  
        DestroyBTNode(b->lchild);  
        DestroyBTNode(b->rchild);  
        free(b);  
    }  
}  
 
运行结果：