2024.2.5

#include
#include
#include
#include
typedef int datatype;
//定义结点结构体
typedef struct Node
{
   datatype data;
   struct Node *next;
}*node;
//创建结点
node creat_node()
{
	node s=(node)malloc(sizeof(struct Node));
	if(NULL==s)//创建失败
	   return NULL;
	s->data=0;
	s->next=NULL;
	return s;
}
//计算最大质数
int prime(int m)
{
	for(int i=m;i>=2;i--)
	{
		int flag=0;
		for(int j=2;j<=sqrt(i);j++)
		{
			if(i%j==0)
			{
				flag=-1;
				break;
			}
		}
		if(flag==0)
			return i;
	}
}
//插入
void insert_hash(int key,int p,node hash[])
{
	int index=key%p; 
    hash[index]; 
	node s=creat_node();
	s->data=key;
	if(hash[index]==NULL)
		hash[index]=s;
	else
	{
		s->next=hash[index];
		hash[index]=s;
	}
}
//哈希查找,成功返回0.失败返回-1
int serch_hash(datatype key,int p,node hash[])
{
	int index=key%p;
	node head=hash[index];
	while(head!=NULL)
	{
		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;//哈希表的长度
    //定义哈希表
	node hash[m];
	for(int i=0;i

#include
#include
#include
int half(int key,int *p,int low,int high)
{
	while(low<=high)
	{
		int mid=(low+high)/2;
		if(*(p+mid)key)
			high=mid-1;
		else return mid;
	}
	return -1;
}
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 input key:");
  scanf("%d",&key);
  int i=half(key,arr,0,len-1);
  if(i==-1)
	  puts("unexist");
		  else
 puts("exist");
		  return 0;
}