二叉树前中后序非递归遍历C语言实现

#include 
#include 
struct treeNode {
	char data;
	struct treeNode* LChild;
	struct treeNode* RChild;
};
struct treeNode* createNode(char data)
{
	struct treeNode* newNode = (struct treeNode *)malloc(sizeof(struct treeNode));
	newNode->data = data;
	newNode->LChild = NULL;
	newNode->RChild = NULL;
	return newNode;
}
void linkNode(struct treeNode* currentNode, struct treeNode* LChildNode, struct treeNode* RChildNode)
{
	currentNode->LChild = LChildNode;
	currentNode->RChild = RChildNode;
}
void printNode(struct treeNode* currentNode)
{
	printf("%c ", currentNode->data);
}
void PreOrder(struct treeNode* root)
{
	if(root == NULL)
		return;
	struct treeNode* stack[10];
	int stackTop = -1;
	struct treeNode* t = root;
	while(stackTop != -1 || t)
	{
		while(t)
		{
			printf("%c ", t->data);
			stack[++stackTop] = t;
			t = t->LChild;
		}
		if(stackTop != -1)
		{
			t = stack[stackTop--];
			t = t->RChild;
		}
	}
}
void InOrder(struct treeNode* root)
{
	if(root == NULL)
		return;
	struct treeNode* stack[10];
	int stackTop = -1;
	struct treeNode* t = root;
	while(stackTop != -1 || t)
	{
		while(t)// 走到树最左边的底部结点
		{
			stack[++stackTop] = t;
			t = t->LChild;
		}
		if(stackTop != -1)
		{
			t = stack[stackTop--];
			printf("%c ", t->data);
			t = t->RChild;
		}
	}
}
void PostOrder(struct treeNode* root)
{
	if(root == NULL)
		return;
	struct treeNode* stack[10];
	int stackTop = -1;
	struct treeNode* t = root;
	struct treeNode* temp;
	while(stackTop != -1 || t)
	{
		while(t)
		{
			stack[++stackTop] = t;
			t = t->LChild;
		}
		t = stack[stackTop];
		if(t->RChild == NULL || t->RChild == temp)
		{
			printf("%c ", t->data);
			stackTop--;
			temp = t;
			t = NULL;
		}
		else
		{
			t = t->RChild;
		}
	}
}
int main()
{
	struct treeNode* A = createNode('A');
	struct treeNode* B = createNode('B');
	struct treeNode* C = createNode('C');
	struct treeNode* D = createNode('D');
	struct treeNode* E = createNode('E');
	struct treeNode* F = createNode('F');
	struct treeNode* G = createNode('G');
	struct treeNode* H = createNode('H');
	linkNode(A, B, C);
	linkNode(B, D, E);
	linkNode(C, F, G);
	linkNode(F, NULL, H);
	PreOrder(A);
	printf("\n");
	InOrder(A);
	printf("\n");
	PostOrder(A);
	printf("\n");
	return 0;
}