C语言--二叉树创建与遍历

#include"stdio.h"
#include"stdlib.h"
struct tree
{
	char data;
	struct tree *lchild;
	struct tree *rchild;
};
//创建二叉树，按照前序遍历方式输入
void createtree(struct tree **T)
{
	char c;
	scanf("%c", &c);
	if(' ' == c)
	{
		*T = NULL;
	}
	else
	{
		*T = (struct tree *)malloc(sizeof(struct tree));
		(*T)->data = c;
		createtree(&(*T)->lchild);
		createtree(&(*T)->rchild);
	}
}
void visit(char c, int level)
{
	printf("%c在第%d层\n", c, level);
}

//前序遍历二叉树
void traversebtree(struct tree *T, int level)
{
	if( T )
	{
		visit(T->data, level);
		traversebtree(T->lchild, level+1);
		traversebtree(T->rchild, level+1);
/*中序遍历	
		traversebtree(T->lchild, level+1);
		visit(T->data, level);
		traversebtree(T->rchild, level+1);
*/
/*后序遍历
		traversebtree(T->lchild, level+1);
		traversebtree(T->rchild, level+1);
		visit(T->data, level);
*/
	}
}
int main()
{
	struct tree *T;
	createtree(&T);
	traversebtree(T, 1);
	return 0;
}