二分查找和斐波那契查找

#include "Search.h"


Search::Search(void)
{
}


Search::~Search(void)
{
}

//二分查找
int Search::Binary_Search(int* a,int n,int key)
{
	//a是按照从小到大排序的数组
	int low,high,mid;
	low = 1;
	high = n;
	while (low < high)
	{
		mid = (low + high)/2;
		if (key < a[mid])
			high = mid-1;
		else if (key > a[mid])
			low = mid + 1;
		else 
			return mid;
	}
	return 0;
}

int F[]={0,1,2,3,5,8,13,21,34,55,89,144};

int Search::Fibonacci_Search(int* a,int key)
{
	int low,mid,i,k;
	low = 1;
	high = n;
	k = 0;
	while (n > F[k]-1) //查找n位于斐波那契数列的位置
		k++;

	for (i = n; i<F[k]-1; i++)
		a[i] = a[n];

	while (low <= high)
	{
		mid = low + F[k-1] - 1; //计算当前分隔的下标
		if (key < a[mid]) //若查找记录小于当前记录
		{
			high = mid - 1;
			k = k - 1;
		}
		else if (key > a[mid])
		{
			low = mid + 1;
			k = k - 2;
		}
		else
		{
			if (mid <= n)
			{
				return mid;
			}
			else
				return n;
		}
	}
	return 0;
}

二叉查找树

结构定义

//二叉树链表节点定义
typedef struct BiTNode
{
	int data;
	struct BiTNode *lchild,*rchild;
}BiTNode,*BiTree;

#include "BinarySearchTree.h"


BinarySearchTree::BinarySearchTree(void)
{
}


BinarySearchTree::~BinarySearchTree(void)
{
}

/*
递归查找二叉树中是否存在Key，指针f指向T的双亲
若查找成功则指针p指向该数据元素节点
否则p指向查找路径上访问的最后一个节点并返回失败
*/
int BinarySearchTree::SearchBST(BiTree T,int key,BiTree f,BiTree *p)
{
	if (!T)  //查找失败
	{
		*p = f;
		return -1;
	}
	else if (key == T->data)  //查找成功
	{
		*p = T;
		return 1;
	}
	else if (key < T->data)
	{ 
		return SearchBST(T->lchild,key,T,p); //左子树继续查找
	}
	else
	{
		return SearchBST(T->rchild,p); //右子树继续查找
	}
}

/*
如果二叉树中不存在关键字等于key的元素，则插入key并返回
*/
int BinarySearchTree::InsertBST(BiTree *T,int key)
{
	BiTree p,s;
	int result = SearchBST(*T,NULL,&p);
	if (result == -1)
	{
		s = (BiTree)malloc(sizeof(BiTree));
		s->data = key;
		s->lchild = s->rchild = NULL;

		if (!p)
		{
			*T = s;
		}
		else if (key < p->data)
		{
			p->lchild = s;
		}
		else
		{
			p->rchild = s;
		}
		return 1;

	}
	else
	{
		return -1;
	}
}

/*
从二叉树中删除节点p，并重接他的左或右子树
*/
int BinarySearchTree::Delete(BiTree *p)
{
	BiTree q,s ;
	if ((*p)->rchild == NULL) //右子树空则只需要重接它的左子树
	{
		q = *p;
		*p = (*p)->lchild;
		free(q);
	}
	else if ((*p)->lchild == NULL) //只需要重新连接它的右子树
	{
		q = *p;
		*p = (*p)->rchild;
		free(q);
	}
	else  //左右子树均不为空
	{
		q = *p;
		s = (*p)->lchild;
		while (s->rchild) //转左，然后向右到尽头
		{
			q = s;
			s = s->rchild;
		}
		(*p)->data = s->data;
		if (q != *p)
		{
			q->rchild = s->lchild;
		}
		else
		{
			q->lchild = s->rchild;
		}
		free(s);
	}
	return 1;

}

/*
若二叉排序树T中存在关键字等于key的数据元素时，则删除数据元素节点
*/
int BinarySearchTree::DeleteBST(BiTree *T,int key)
{
	if (!*T) 
		return -1;
	else
	{
		if (key == (*T)->data)
		{
			return Delete(T);
		}
		else if (key < (*T)->data)
		{
			return DeleteBST(&(*T)->lchild,key);
		}
		else
		{
			return DeleteBST(&(*T)->rchild,key);
		}
	}
}