树的存储与遍历_noorder(bitree *r)-优快云博客

本文介绍了一种使用C语言实现的二叉树结构，并通过递归方式实现了前序、中序和后序遍历。此外，还利用队列实现了层次遍历，展示了队列的基本操作如创建空队列、入队和出队等。

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#include <stdio.h>
#include <stdlib.h>

#define N 10

typedef int datatype;

typedef struct _btnode_
{
datatype no;
struct _btnode_ *lchild, *rchild;
} bitree;

typedef struct
{
bitree *data[N];
int front, rear;
} sequeue;

sequeue *CreateEmptyQueue()
{
sequeue *sq;

sq = (sequeue *)malloc(sizeof(sequeue));
sq->front = sq->rear = 0;

return sq;
}

void EnQueue(sequeue *sq, bitree *r)
{
sq->rear = (sq->rear + 1) % N;
sq->data[sq->rear] = r;

return;
}

bitree *DeQueue(sequeue *sq)
{
sq->front = (sq->front + 1) % N;

return sq->data[sq->front];
}

int EmptyQueue(sequeue *sq)
{
return (sq->front == sq->rear);
}

bitree *CreateBitree(int i, int n)
{
bitree *root;

root = (bitree *)malloc(sizeof(bitree));
root->no = i;

if (2*i <= n)
{
  root->lchild = CreateBitree(2*i, n);
}
else
{
  root->lchild = NULL;
}

if ((2*i+1) <= n)
{
  root->rchild = CreateBitree(2*i+1, n);
}
else
{
  root->rchild = NULL;
}

return root;
}

void PreOrder(bitree *root)
{
printf("%d ", root->no);
if (root->lchild != NULL) PreOrder(root->lchild);
if (root->rchild != NULL) PreOrder(root->rchild);

return;
}

void InOrder(bitree *root)
{
if (root->lchild != NULL) InOrder(root->lchild);
printf("%d ", root->no);
if (root->rchild != NULL) InOrder(root->rchild);

return;
}

void PostOrder(bitree *root)
{
if (root->lchild != NULL) PostOrder(root->lchild);
if (root->rchild != NULL) PostOrder(root->rchild);
printf("%d ", root->no);

return;
}

void NoOrder(bitree *root)
{
sequeue *sq;
bitree *r;

sq = CreateEmptyQueue();
EnQueue(sq, root);
while ( ! EmptyQueue(sq) )
{
  r = DeQueue(sq);
  printf("%d ", r->no);
  if (r->lchild != NULL) EnQueue(sq, r->lchild);
  if (r->rchild != NULL) EnQueue(sq, r->rchild);
}

printf("\n");
}

int main()
{
bitree *root;

root = CreateBitree(1, 10);
printf("PreOrder : ");
PreOrder(root);
printf("\n");

printf("InOrder : ");
InOrder(root);
printf("\n");

printf("PostOrder : ");
PostOrder(root);
printf("\n");

printf("NoOrder : ");
NoOrder(root);

return 0;
}