二叉树顺序表示的实现

#include <stdio.h>
#include <string.h>
#include <math.h>

#define OK 1
#define ERROR 0
#define TRUE 1
#define FALSE 0
#define MAX_TREE_SIZE 100

typedef char seq_bitree[MAX_TREE_SIZE];	//可以把seq_bitree当做一个数据类型用了

char nil = ' ';	//字符型节点设' '为空节点
int (*visit_fun)(char);

/*
初始化二叉树，结点值赋为nil
*/
void init_seq_bitree(seq_bitree tree)
{
	int i = 0;
	for(i = 0; i < MAX_TREE_SIZE; i++)
	{
		tree[i] = nil;
	}

	return ;
}

/*
根据输入的层序str_tree，创建二叉树
*/
void create_seq_bitree(seq_bitree tree, char *str_tree)
{
	int i = 0;
	int len = 0;
	len = strlen(str_tree);

	for(i = 0; i < len; i++)
	{
		if(str_tree[i] == 0)
		{
			tree[i] = nil;
		}
		else
		{
			tree[i] = str_tree[i];
		}

		if((i != 0) && (tree[(i + 1) / 2 - 1] == nil) && (tree[i] != nil))
		{
			printf("出现了无父节点的非根节点!\n");
			exit(ERROR);
		}
	}

	for(i = len; i < MAX_TREE_SIZE; i++)	//将剩余的部分置为空节点
	{
		tree[i] = nil;
	}

	return ;
}

/*
功能：	判断二叉树是否为空
返回：	TRUE 为空；FLASE 非空
*/
int is_bitree_empty(seq_bitree tree)
{
	if(tree[0] == nil)
	{
		return TRUE;
	}
	else
	{
		return ERROR;	
	}

}

/*
获取二叉树的深度
*/
int get_bitree_depth(seq_bitree tree)
{
	int i = 0;
	int depth = 0;

	for(i = (MAX_TREE_SIZE - 1); i >= 0; i--)
	{
		if(tree[i] != nil)
		{
			break;
		}
	}
	
	do
	{
		depth++;
	}while(i >= (int)pow(2, depth));


	return depth;
}

/*供preorder_traverse调用*/
void pre_traverse(seq_bitree tree, int index)
{
	visit_fun(tree[index]);
	if(tree[2 * index + 1] != nil)
	{
		pre_traverse(tree, (2 * index + 1));
	}
	if(tree[2 * index + 2] != nil)
	{
		pre_traverse(tree, (2 * index + 2));
	}
}

/*
先序遍历二叉树
*/
int preorder_traverse(seq_bitree tree, int (*visit)(char))
{
	visit_fun = visit;

	if(is_bitree_empty(tree))
	{
		printf("the tree is empty.\n");
	}
	pre_traverse(tree, 0);

	return OK;
}

/*供inorder_traverse调用*/
void in_traverse(seq_bitree tree, int index)
{
	if(tree[2 * index + 1] != nil)
	{
		in_traverse(tree, (2 * index + 1));
	}

	visit_fun(tree[index]);

	if(tree[2 * index + 2] != nil)
	{
		in_traverse(tree, (2 * index + 2));
	}
}

/*
中序遍历二叉树
*/
int inorder_traverse(seq_bitree tree, int (*visit)(char))
{
	visit_fun = visit;

	if(is_bitree_empty(tree))
	{
		printf("the tree is empty.\n");
	}
	in_traverse(tree, 0);

	return OK;
}

/*供postorder_traverse调用*/
void post_traverse(seq_bitree tree, int index)
{
	if(tree[2 * index + 1] != nil)
	{
		post_traverse(tree, (2 * index + 1));
	}

	if(tree[2 * index + 2] != nil)
	{
		post_traverse(tree, (2 * index + 2));
	}

	visit_fun(tree[index]);
}

/*
后序遍历二叉树
*/
int postorder_traverse(seq_bitree tree, int (*visit)(char))
{
	visit_fun = visit;

	if(is_bitree_empty(tree))
	{
		printf("the tree is empty.\n");
	}
	post_traverse(tree, 0);

	return OK;
}

/*
按层遍历二叉树
*/
int level_order_traverse(seq_bitree tree, int (*visit)(char))
{
	int i = MAX_TREE_SIZE - 1;
	int j = 0;
	visit_fun = visit;

	if(is_bitree_empty(tree))
	{
		printf("the tree is empty.\n");
		return OK;
	}
	while(tree[i] != nil)
	{
		i--;
	}

	for(j = 0; j <+ i; j++)
	{
		if(tree[j] == nil)	//不存在的结点不打印
		{
			continue;
		}
		visit_fun(tree[j]);
	}
	printf("\n");

	return OK;
}

int visit(char e)
{
	printf("%c ", e);
	return OK;
}

int main(int argc, char *argv[])
{
	seq_bitree tree;

	char str_tree[MAX_TREE_SIZE] = "abcde    fg";
	//测试数据，假设二叉树层序遍历如上（' '表示该处无节点）
	
	init_seq_bitree(tree);
	create_seq_bitree(tree, str_tree);
	if(is_bitree_empty(tree))
	{
		printf("the bitree is empty.\n");
		return 0;
	}
	printf("the depth of the bitree is %d\n", get_bitree_depth(tree));
	printf("先序遍历二叉树:\n");
	preorder_traverse(tree, visit);
	printf("\n中序遍历二叉树:\n");
	inorder_traverse(tree, visit);
	printf("\n后序遍历二叉树:\n");
	postorder_traverse(tree, visit);
	printf("\n按层遍历二叉树:\n");
	level_order_traverse(tree, visit);

	return 0;
}