二叉树程序演示

#include
#include
struct BTNode{
	char character;
	struct BTNode* pLchild;
	struct BTNode* pRchild;
};
struct BTNode* CreatBTree(void);
void PreTraverseTree(struct BTNode*);//先序遍历 
void InTraverseTree(struct BTNode*);//中序遍历 
void PostTraverseTree(struct BTNode*);//后序遍历 
int main(void)
{
	struct BTNode* pT=NULL;
	pT=CreatBTree();
	PreTraverseTree(pT);
	printf("nn");
	InTraverseTree(pT);
	printf("nn");
	PostTraverseTree(pT);
	return 0;
}
struct BTNode* CreatBTree(void)
{
	struct BTNode* pA=(struct BTNode*)malloc(sizeof(struct BTNode));
	struct BTNode* pB=(struct BTNode*)malloc(sizeof(struct BTNode));
	struct BTNode* pC=(struct BTNode*)malloc(sizeof(struct BTNode));
	struct BTNode* pD=(struct BTNode*)malloc(sizeof(struct BTNode));
	struct BTNode* pE=(struct BTNode*)malloc(sizeof(struct BTNode));
	pA->character='A';
	pB->character='B';
	pC->character='C';
	pD->character='D';
	pE->character='E';
	pA->pLchild=pB;
	pA->pRchild=pC;
	pB->pLchild=pB->pRchild=NULL;
	pC->pLchild=pD;
	pC->pRchild=NULL;
	pD->pLchild=NULL;
	pD->pRchild=pE;
	pE->pRchild=pE->pLchild=NULL;
	return pA;
}
void PreTraverseTree(struct BTNode* pT)
{
	if(pT!=NULL)
	{
		printf("%cn",pT->character);
		if(pT->pLchild!=NULL)
		PreTraverseTree(pT->pLchild);
		if(pT->pRchild!=NULL)
		PreTraverseTree(pT->pRchild);
	}
}
void InTraverseTree(struct BTNode* pT)
{
	if(pT!=NULL)
	{
		if(pT->pLchild!=NULL)
		InTraverseTree(pT->pLchild);
		printf("%cn",pT->character);
		InTraverseTree(pT->pRchild);
	}
}
void PostTraverseTree(struct BTNode* pT)
{
	if(pT!=NULL)
	{
		if(pT->pLchild!=NULL)
		PostTraverseTree(pT->pLchild);
		if(pT->pRchild!=NULL)
		PostTraverseTree(pT->pRchild);
		printf("%cn",pT->character); 
	}
}