非递归遍历二叉树的四种策略-先序、中序、后序和层序

 先序遍历二叉树算法1

 

// Copyright (c) 2009, ALex ZhonG. All rights reserved.

Status PreOrderTraverse(BiTree T, Status (Visit *)(TElemType e))
{
    InitStack(S);
    Push(S, T);
    p = T;//或 GetTop(S, p);
    while(!StackEmpty(S) && p)
    {
        while(p)
        {
            if(!Visit(p->data))
                return ERROR;
            Push(p->rchild);
            p = p->lchild;
        }
        Pop(S, p);
    }
    DestroyStack(S);
    return OK;
}

 

 

先序遍历二叉树算法2

 

// Copyright (c) 2009, ALex ZhonG. All rights reserved.

Status PreOrderTraverse(BiTree T, Status (Visit *)(TelemType))
{
    InitStack(S);
    Push(S, T);
    p = T;
    while(!StackEmpty(S) && p)
    {
        while(p)
        {
            if(!Visit(p->data))
                return ERROR;
            Push(S, p);
            p = p->lchild;
        }
        if(!StackEmpty(S))
        {
            Pop(S, p);
            p = p->rchild;
        }
    }
    DestroyStack(S);
    return OK;
}

 

 

中序遍历二叉树算法

 

// Copyright (c) 2009, ALex ZhonG. All rights reserved.

Status InOrderTraverse(BiTree T, Status (Visit *)(TelemType e))
{
    InitStack(S);
    Push(S, T)'
    p = T;
    while(!StackEmpty(S) && p)
    {
        while(p)
        {
            Push(S, p);
            p = p ->lchild;
        }
        Pop(S, p);
        if(!Visit(p->data))
            return ERROR;
        p = p->rchild;
    }
    DestroyStack(S);
    return OK;
}

 

 

后序遍历二叉树算法

 

// Copyright (c) 2009, ALex ZhonG. All rights reserved.

Status PostOrderTraverse(BiTree T, Status (Visit *)(TelemType e))
{
    InitStack(S);
    Push(S, T);
    p = T;
    while(!StackEmpty(S) && p)
    {
        if(p)
        {／／一直走到最左下的结点
            Push(S, p);
            p = p->lchild;
        }
        else
        {//p为NULL时
            GetTop(S, p);
            if(p->rchild && p->rchild != r)
            {//p有右孩子或p的右孩子不是刚刚被访问的
                p = p->rchild;
                Push(S, p);
                p = p->lchild;
            }
            else
            {//p无右孩子或p右孩子刚刚被访问过时
                Pop(S, p);
                Visit(p->data);
                r = p;
                p = NULL;
            }
        }
    }
    DestroyStack(S);
    return OK;
}

 

 

层序遍历二叉树算法

 

// Copyright (c) 2009, ALex ZhonG. All rights reserved.

Status LevelOrderTraverse(BiTree T, Status (Visit *)(TelemType e))
{
    InitQueue(Q);
    p = T;
    if(p)
    {
        if(!Visit(p->data)
            return ERROR;
        EnQueue(Q, p->lchild);
        EnQueue(Q, p->rchild);
        while(Q)
        {
            DeQueue(Q, p);
            if(!Visit(p->data))
                return ERROR;
            if(p->lchild)
                EnQueue(Q, p->lchild);
            if(p->rchild)
                EnQueue(Q, p->rchild);
        }
    }
    return OK;
}

 

 

欢迎讨论、批评和指正！

ALex ZhonG

原文链接：http://blog.csdn.net/poechant/article/details/4811531