[數據結構]二叉查找樹 簡單實現

/*
Name：二叉查找樹 簡單實現 

Actor：HT

Time：2015年10月11日

Error Reporte:	1.子函數中給指針賦予新的地址的時候，不要忘記引用...
				2.找前驅，刪點的時候，一定要搞清楚邏輯

*/

#include"stdio.h"
#include"string.h"
#include"stdlib.h"

#define N 10010

struct DFT
{
	int key;
	DFT* p;
	DFT* left;
	DFT* right;
};

void tinsert(DFT* &root,int a)	//BUG點 由於是malloc 別忘了引用
{
	int i, j;
	DFT *fin = root, *t = NULL;
	for (;;)
	{
		if (root == NULL)		//根節點
		{
			root = (DFT*)malloc(sizeof(DFT));
			root->key = a;
			root->left = NULL;
			root->right = NULL;
			root->p = t;
			root->key = a;
			break;
		}
		else if (a <= fin->key)	//左
		{
			if (fin->left != NULL)
			{
				fin = fin->left;
			}
			else
			{
				fin->left = (DFT*)malloc(sizeof(DFT));
				fin->left->key = a;
				fin->left->left = NULL;
				fin->left->right = NULL;
				fin->left->p = fin;
				break;
			}
		}
		else if (a > fin->key)	//右
		{
			if (fin->right != NULL)
			{
				fin = fin->right;
			}
			else
			{
				fin->right = (DFT*)malloc(sizeof(DFT));
				fin->right->key = a;
				fin->right->left = NULL;
				fin->right->right = NULL;
				fin->right->p = fin;
				break;
			}
		}
	}
}

DFT* tsuccessor(DFT* &root, int a)
{
	DFT* p = root;
	for (;;)				//查找點
	{
		if (p == NULL)
		{
			printf("No point\n");
			return NULL;
		}
		if (p->key == a)
			break;
		else if (a < p->key)
			p = p->left;
		else if (a > p->key)
			p = p->right;
	}
	if (p->right != NULL)				//找最大右兒子
	{
		p = p->right;
	D:		if (p->left != NULL)
	{
				p = p->left;
				goto D;
	}
			return p;
	}
	else if (p->p != root->p)				//最小的祖上
	{
	K:		if (p == p->p->left)
		return p->p;
			else
			{
				p = p->p;
				if (p->p != root->p)
					goto K;
				else
				{
					printf("No successor\n");
					return NULL;
				}
			}
	}
	else
	{
		//printf("No successor\n");
		return NULL;
	}
}

DFT* tpredecessor(DFT* &root, int a)
{
	DFT* p = root;
	for (;;)				//查找點
	{
		if (p == NULL)
		{
			printf("No point\n");
			return NULL;
		}
		if (p->key == a)
			break;
		else if (a < p->key)
			p = p->left;
		else if (a > p->key)
			p = p->right;
	}
	if (p->left != NULL)
	{
		p = p->left;
	D:		if (p->right != NULL)
	{
				p = p->right;
				goto D;
	}
			return p;
	}
	else if (p->p != root->p)
	{
	K:		if (p == p->p->right)
		return p->p;
			else
			{
				p = p->p;
				if (p->p != root->p)
					goto K;
				else
				{
					printf("No predecessor\n");
					return NULL;
				}
			}
	}
	else
	{
		//printf("No predecessor\n");
		return NULL;
	}
}


void tdelete(DFT*& root ,int a)
{
	DFT* p = root;
	for (;;)				//查找點
	{
		if (p == NULL)
		{
			printf("No point\n");
			return;
		}
		if (p->key == a)
			break;
		else if (a < p->key)
			p = p->left;
		else if (a > p->key)
			p = p->right;
	}
	if (p->left == NULL&&p->right == NULL)		//無後
	{
		if (p->p != NULL)
		{
			if (p->p->left == p)
			{
				p->p->left = NULL;
				free(p);
			}
			else if (p->p->right == p)
			{
				p->p->right = NULL;
				free(p);
			}
		}
		else
			free(p);
	}
	else if (p->left != NULL && p->right == NULL)	//有左兒子
	{
		if (p->p != NULL)
		{
			if (p->p->left == p)
			{
				p->p->left = p->left;
				p->left->p = p->p;
				free(p);
			}
			else if (p->p->right == p)
			{
				p->p->right = p->left;
				p->left->p = p->p;
				free(p);
			}
		}
		else
		{
			if (p == root)
			{
				root = p->left;
				root->p = NULL;		//BUG點
				free(p);
			}

		}
	}
	else if (p->left == NULL && p->right != NULL)	//有右兒子
	{
		if (p->p != NULL)
		{
			if (p->p->left == p)
			{
				p->p->left = p->right;
				p->right->p = p->p;
				free(p);
			}
			else if (p->p->right == p)
			{
				p->p->right = p->right;
				p->right->p = p->p;
				free(p);
			}
		}
		else
		{
			if (p == root)
			{
				root = p->right;
				root->p = NULL; //BUG點
				free(p);
			}

		}
	}
	else	//倆兒子 刪除改點的後繼點，然後用後繼點的值代替該點
	{
		DFT* tp = tsuccessor(p, p->key);
		int ttp = tp->key;
		tdelete(root,tp->key);
		p->key = ttp;
	}
}

void twalk(DFT * point)
{ 
	if (point->left != NULL)
		twalk(point->left);
	printf("%d ", point->key);
	if (point->right != NULL)
		twalk(point->right);
}

void tdestory(DFT * point)
{
	if (point->left != NULL)
		tdestory(point->left);
	if (point->right != NULL)
		tdestory(point->right);
	free(point);
}

int main()
{
	int i, j;
	DFT *root = NULL;

	//插入 遍歷部分測試
	int a[7] = { 5, 3, 8, 4, 2, 9, 7};
	for (i = 0; i < 7; i++)
	{
		tinsert(root, a[i]);
	}
	twalk(root);
	printf("\n");

	//前驅 後繼部分測試
	//DFT* tt;
	//int ttt;
	//for (i = 0; i < 7; i++)
	//{
	//	scanf("%d", &ttt);

	//	tt = tsuccessor(root, ttt);
	//	if (tt != NULL)printf("%d's successor is %d\n", ttt, tt->key);
	//}

	//刪除部分測試
	//DFT* tt;
	//int ttt;
	//for (i = 0; i < 7; i++)
	//{
	//	scanf("%d", &ttt);

	//	tdelete(root, ttt);
	//	twalk(root);
	//	printf("\n");
	//}

	tdestory(root);

	system("pause");
	return 0;
}