23、数据结构/查找相关练习20240205

一、请编程实现哈希表的创建存储数组{12,24,234,234,23,234,23},输入key查找的值，实现查找功能。

代码：

#include
#include
#include
#include
typedef struct Node
{
	int data;
	struct node *next;
}*list;
int max_prime(int m)
{
	int i=m;
	for(i;i>1;i--)
	{
		int flag=0;
		for(int j=2;j<=sqrt(i);j++)
		{
			if(i%j==0)
			{
				flag=-1;
				break;
			}
		}
		if(flag==0)
			return i;
	}
}
list create_node()
{
	list s=(list)malloc(sizeof(struct Node));
	if(NULL==s)
		return NULL;
	s->data=0;
	s->next=NULL;
	return s;
}
void insert_hash(int arr,int p,list hash[])
{
	int value=arr%p;
	list s=create_node();
	s->data=arr;
	if(NULL==hash[value])
	{
		hash[value]=s;
	}
	else
	{
		s->next=hash[value];
		hash[value]=s;
	}
}
void output_hash(list hash[],int m)
{
	for(int i=0;idata);
		p=p->next;
		}
		puts("end");
	}
}
int search_hash(list hash[],int p,int key)
{
	int value=key%p;
	list head=hash[value];
	while(head)
	{
		if(head->data==key)
			return 0;
		head=head->next;
	}
	return -1;
}
int main(int argc, const char *argv[])
{
	int arr[]={12,24,234,234,23,234,23};
	int len=sizeof(arr)/sizeof(arr[0]);
	int m=len*4/3;//哈希表长
	list hash[m];
	for(int i=0;i

运行：

二、 现有数组{12,23,45,56,445,5676,6888},请输入key实现二分查找。

代码：

#include
#include
#include
enum BISE
{
	SUCCESS,
	FAILURE
};
int binary_search(int *p,int len,int key)
{
	int low=0,high=len-1;
	while(low<=high)
	{
		int mid=(low+high)/2;
		if(*(p+mid)key)
		{
			high=mid-1;
		}
	}
	return FAILURE;
}
int main(int argc, const char *argv[])
{
	int arr[]={12,23,45,56,445,5676,6888};
	int len=sizeof(arr)/sizeof(arr[0]);
	int key;
	printf("please enter search key:");
	scanf("%d",&key);
	int flag=binary_search(arr,len,key);
	if(flag==SUCCESS)
		puts("exists");
	else
		puts("unexists");

	return 0;
}

代码运行：