C語言按層次遍歷二叉樹算法

#define MaxSize 1000
typedef char ElemType;
typedef struct node
{
    ElemType data;
    struct node lchild;
    struct node rchild;
} BTNode;
//創建二叉樹
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];
    }

}
//層次遍歷算法
void LevelOrder(BTNode b)
{
    BTNode p;
    BTNode qu[MaxSize];
    int front,rear;
    front=rear=-1;
    rear++;
    qu[rear]=b;
    while(front != rear)
    {
        front=(front+1)%MaxSize;
        p=qu[front];
        printf("%c ",p->data);


    if(p->lchild!=NULL)
    {
        rear=(rear+1)%MaxSize;
        qu[rear]=p->lchild;
    }

    if(p->rchild!=NULL)
    {
        rear=(rear+1)%MaxSize;
        qu[rear]=p->rchild;
    }
}

}
//主函數
int main()
{
    BTNode b,h;
    char s[MaxSize] = "A(B(D(,G)),C(E,F))";

CreateBTNode(b,s);
printf("層次遍歷算法的訪問次序為：");
LevelOrder(b);
printf("\n請輸入二叉樹括號表示法字符串：\n");
return 0;

} 
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