数据结构：二叉树

老师的代码：

#include 
#include 

#define QUEUE_SIZE 5


typedef struct BTNode{
	char element;
	BTNode* left;
	BTNode* right;
}BTNode, *BTNodePtr;


typedef struct BTNodePtrQueue{
	BTNodePtr* nodePtrs;
	int front;
	int rear;
}BTNodePtrQueue, *QueuePtr;


QueuePtr initQueue(){
	QueuePtr resultQueuePtr = (QueuePtr)malloc(sizeof(struct BTNodePtrQueue));
	resultQueuePtr->nodePtrs = (BTNodePtr*)malloc(QUEUE_SIZE * sizeof(BTNodePtr));
	resultQueuePtr->front = 0;
	resultQueuePtr->rear = 1;
	return resultQueuePtr;
}//Of initQueue


bool isQueueEmpty(QueuePtr paraQueuePtr){
	if ((paraQueuePtr->front + 1) % QUEUE_SIZE == paraQueuePtr->rear) {
		return true;
	}//Of if

	return false;
}//Of isQueueEmpty


void enqueue(QueuePtr paraQueuePtr, BTNodePtr paraBTNodePtr){
	printf("front = %d, rear = %d.rn", paraQueuePtr->front, paraQueuePtr->rear);
	if ((paraQueuePtr->rear + 1) % QUEUE_SIZE == paraQueuePtr->front % QUEUE_SIZE) {
		printf("Error, trying to enqueue %c. queue full.rn", paraBTNodePtr->element);
		return;
	}//Of if
	paraQueuePtr->nodePtrs[paraQueuePtr->rear] = paraBTNodePtr;
	paraQueuePtr->rear = (paraQueuePtr->rear + 1) % QUEUE_SIZE;
	printf("enqueue %c ends.rn", paraBTNodePtr->element);
}//Of enqueue


BTNodePtr dequeue(QueuePtr paraQueuePtr){
	if (isQueueEmpty(paraQueuePtr)) {
		printf("Error, empty queuern");
		return NULL;
	}//Of if

	paraQueuePtr->front = (paraQueuePtr->front + 1) % QUEUE_SIZE;
	//BTNodePtr tempPtr = paraQueuePtr->nodePtrs[paraQueuePtr->front + 1];

	printf("dequeue %c ends.rn", paraQueuePtr->nodePtrs[paraQueuePtr->front]->element);
	return paraQueuePtr->nodePtrs[paraQueuePtr->front];
}//Of dequeue


BTNodePtr constructBTNode(char paraChar){
	BTNodePtr resultPtr = (BTNodePtr)malloc(sizeof(BTNode));
	resultPtr->element = paraChar;
	resultPtr->left = NULL;
	resultPtr->right = NULL;
	return resultPtr;
}//Of constructBTNode


BTNodePtr stringToBTree(char* paraString){
	int i;
	char ch;

	//Use a queue to manage the pointers
	QueuePtr tempQueuePtr = initQueue();

	BTNodePtr resultHeader;
	BTNodePtr tempParent, tempLeftChild, tempRightChild;
	i = 0;
	ch = paraString[i];
	resultHeader = constructBTNode(ch);
	enqueue(tempQueuePtr, resultHeader);

	while(!isQueueEmpty(tempQueuePtr)) {
		tempParent = dequeue(tempQueuePtr);

		//The left child
		i ++;
		ch = paraString[i];
		if (ch == '#') {
			tempParent->left = NULL;
		} else {
			tempLeftChild = constructBTNode(ch);
			enqueue(tempQueuePtr, tempLeftChild);
			tempParent->left = tempLeftChild;
		}//Of if

		
		//The right child
		i ++;
		ch = paraString[i];
		if (ch == '#') {
			tempParent->right = NULL;
		} else {
			tempRightChild = constructBTNode(ch);
			enqueue(tempQueuePtr, tempRightChild);
			tempParent->right = tempRightChild;
		}//Of if
	}//Of while

	return resultHeader;
}//Of stringToBTree


void levelwise(BTNodePtr paraTreePtr){
	//Use a queue to manage the pointers
	char tempString[100];
	int i = 0;
	QueuePtr tempQueuePtr = initQueue();
	BTNodePtr tempNodePtr;
	enqueue(tempQueuePtr, paraTreePtr);
	while(!isQueueEmpty(tempQueuePtr)) {
		tempNodePtr = dequeue(tempQueuePtr);
		
		//For output.
		tempString[i] = tempNodePtr->element;
		i ++;

		if (tempNodePtr->left != NULL){
			enqueue(tempQueuePtr, tempNodePtr->left);
		}//Of if
		if (tempNodePtr->right != NULL){
			enqueue(tempQueuePtr, tempNodePtr->right);
		}//Of if
	}//Of while
	tempString[i] = '';

	printf("Levelwise: %srn", tempString);
}//Of levelwise


void preorder(BTNodePtr tempPtr){
	if (tempPtr == NULL){
		return;
	}//Of if

	printf("%c", tempPtr->element);
	preorder(tempPtr->left);
	preorder(tempPtr->right);
}//Of preorder


void inorder(BTNodePtr tempPtr){
	if (tempPtr == NULL) {
		return;
	}//Of if

	inorder(tempPtr->left);
	printf("%c", tempPtr->element);
	inorder(tempPtr->right);
}//Of inorder


void postorder(BTNodePtr tempPtr){
	if (tempPtr == NULL) {
		return;
	}//Of if

	postorder(tempPtr->left);
	postorder(tempPtr->right);
	printf("%c", tempPtr->element);
}//Of postorder


int main(){
	BTNodePtr tempHeader;
	tempHeader = constructBTNode('c');
	printf("There is only one node. Preorder visit: ");
	preorder(tempHeader);
	printf("rn");

	char* tempString = "acde#bf######";

	tempHeader = stringToBTree(tempString);
	printf("Preorder: ");
	preorder(tempHeader);
	printf("rn");
	printf("Inorder: ");
	inorder(tempHeader);
	printf("rn");
	printf("Postorder: ");
	postorder(tempHeader);
	printf("rn");
	printf("Levelwise: ");
	levelwise(tempHeader);
	printf("rn");

	return 1;
}//Of main

我的代码：

#include 
#include 
#include 
#define QUEUE_SIZE 5//队列空间大小 

typedef struct BTNode{
	char element;
	struct BTNode* leftChild;
	struct BTNode* rightChild;
}BTNode,*BTNodePtr;
 
typedef struct BTNodeQueue{
	BTNodePtr* nodePtrs; //队列里存放的是二叉树结点的地址
	int front;
	int rear; 
}BTNodeQueue,*BTNodeQueuePtr;
 
BTNodeQueuePtr initQueue(){
	BTNodeQueuePtr QueuePtr=(BTNodeQueuePtr)malloc(sizeof(struct BTNodeQueue));
	QueuePtr->nodePtrs=(BTNodePtr*)malloc(QUEUE_SIZE*sizeof(struct BTNode));//队列的空间用来存二叉树结点的地址
	QueuePtr->front=0;
	QueuePtr->rear=1;
	return QueuePtr;
} 

bool isQueueEmpty(BTNodeQueuePtr paraQueue){
	if((paraQueue->front+1)%QUEUE_SIZE==paraQueue->rear){
		return true;
	}
	return false;
}

void enqueue(BTNodeQueuePtr paraQueue,BTNodePtr paraBTNodePtr){
	//判断队列是否已满
	if((paraQueue->rear+1)%QUEUE_SIZE==paraQueue->front%QUEUE_SIZE){
		printf("The queue is full.Cannot enqueue data %c.rn",paraBTNodePtr->element);
	} 
	//结点指针入队
	paraQueue->nodePtrs[paraQueue->rear]=paraBTNodePtr;
	paraQueue->rear=(paraQueue->rear+1)%QUEUE_SIZE; 
	printf("%c has enqueued.rn",paraBTNodePtr->element);
}

BTNodePtr dequeue(BTNodeQueuePtr paraQueue){
	//判断队列是否为空
	if(paraQueue->front==paraQueue->rear){
		printf("The queue is empty.Cannot dequeue element.rn");
		return NULL;
	}
	//结点指针出队
	paraQueue->front=(paraQueue->front+1)%QUEUE_SIZE;//front最初指向出队元素的前面的一个位置，现在让front指向出队指针 
	printf("dequeue %c ends.rn",paraQueue->nodePtrs[paraQueue->front]->element);
	return paraQueue->nodePtrs[paraQueue->front]; 
}

BTNodePtr constructBTNode(char parachar){
	BTNodePtr tempNode=(BTNodePtr)malloc(sizeof(struct BTNode));
	tempNode->element=parachar;
	tempNode->leftChild=NULL;
	tempNode->rightChild=NULL;
	return tempNode;
}

BTNodePtr stringToBTree(char* paraString){
	int i,ch;
	//初始化指针队列 
	BTNodeQueuePtr tempQueue=initQueue();
	//头结点指针入队 
	BTNodePtr Header,tempParent,tempLeftChild,tempRightChild;
	i=0;ch=paraString[i];Header=constructBTNode(ch);
	enqueue(tempQueue,Header);
	//创建子树 
	while(!isQueueEmpty(tempQueue)){
		tempParent=dequeue(tempQueue);
		//leftchild 
		i++;ch=paraString[i];
		if(ch=='#'){
			tempParent->leftChild=NULL;
		}else{
			tempLeftChild=constructBTNode(ch);
			enqueue(tempQueue,tempLeftChild);
			tempParent->leftChild=tempLeftChild;
		}
		//rightchild
		i++;ch=paraString[i];
		if(ch=='#'){
			tempParent->rightChild=NULL;
		}else{
			tempRightChild=constructBTNode(ch);
			enqueue(tempQueue,tempRightChild);
			tempParent->rightChild=tempRightChild;
		}
	}//Of while
	return Header;
}

void levelwise(BTNodePtr paraTreePtr){
	BTNodePtr tempNodePtr;//接受出队的结点指针 
	int i=0;char tempString[100];//将结点的字符依次保存在字符串中，方便输出 
	//初始化队列存储结点指针
	BTNodeQueuePtr tempQueue=initQueue();
	enqueue(tempQueue,paraTreePtr); 
	while(!isQueueEmpty(tempQueue)){
		tempNodePtr=dequeue(tempQueue);
		tempString[i]=tempNodePtr->element;
		i++;
		if(tempNodePtr->leftChild!=NULL){
			enqueue(tempQueue,tempNodePtr->leftChild);
		}
		if(tempNodePtr->rightChild!=NULL){
			enqueue(tempQueue,tempNodePtr->rightChild);
		}
	}
	tempString[i]=='';
	printf("Levelwise:%srn",tempString);
} 

void preOrder(BTNodePtr tempPtr){
	if(tempPtr==NULL){
		return;
	} 
	printf("%c",tempPtr->element);
	preOrder(tempPtr->leftChild);
	preOrder(tempPtr->rightChild);
} 

void inOrder(BTNodePtr tempPtr){
	if(tempPtr==NULL){
		return;
	} 
	inOrder(tempPtr->leftChild);
	printf("%c",tempPtr->element);
	inOrder(tempPtr->rightChild);
}
 
void poOrder(BTNodePtr tempPtr){
	if(tempPtr==NULL){
		return;
	}
	poOrder(tempPtr->leftChild);
	poOrder(tempPtr->rightChild);
	printf("%c",tempPtr->element);
}
int main(){
	BTNodePtr tempHeader;//保存根节点 
	//单个字符 
	tempHeader=constructBTNode('c');
	printf("There is only one node.preOrder visit:rn");
	preOrder(tempHeader);
	printf("rn");
	//字符串
	printf("---- the stringToBTree begins. ----rn");
	char *tempString="acde#bf######";
	tempHeader=stringToBTree(tempString);
	printf("---- the stringToBTree ends. ----rn");
	printf("---- traversal begins, ----rn");
	printf("preOrder:");
	preOrder(tempHeader);
	printf("rn");
	printf("inOrder:");
	inOrder(tempHeader);
	printf("rn");
	printf("poOrder:");
	poOrder(tempHeader);
	printf("rn");
	printf("Levelwise：rn");
	levelwise(tempHeader);
	printf("---- traversal ends, ----rn");
	return 0; 
}

运行结果：