C语言通用交换和查询函数

C语言通用交换和查询函数

#include
#include
#include
using namespace std;

void swap(void *a,void *b,int size)
{
	unsigned char t[size];
	memcpy(t,a,size);
	memcpy(a,b,size);
	memcpy(b,t,size);
}

// n数组大小 m找的数据类型占多少个字节 
// 通用查找方法1 
void* search1(void* a,void* k,int n,int m)
{
	for(int i = 0; i < n; i++)
	{
		void* loc = (char*)a + i * m;
		if(memcmp(loc,k,m) == 0)
		return loc; 
	 } 
	 return NULL;
}

// 通用查找方法2(字符串查找
 
void* search2(void* a,void* k,int n,int m,int (*cmp1)(void* ,void*))
{
	for(int i = 0;i < n; i++)
	{
		void* addr = (char*)a + i*m;
		if(cmp1(addr,k) == 0)
		{
			return addr;
		}
	}	
	return NULL;
} 

// 字符串比较 
int cmp1(void* x,void* y)
{
	char* a= *(char**)x;
	char* b= *(char**)y;
	return strcmp(a,b);
}

int main()
{
	int x = 10;
	int y = 20;
	int arr[5] = {0,1,2,3,4};
	int lenArr = 5;
	int k = 2;
	swap(&x,&y,sizeof(int));
	printf("x = %d, y = %d\n",x,y); 
	int result = *(int *)search1(arr,&k,lenArr,sizeof(int));
	printf("在int数组中查找到的元素: result = %d\n",result);
	if(result != 0)
	{
		printf("存在该元素!\n");
	}else{
		printf("不存在该元素!\n");
	}
	char* books[] = {"book1","book2","book3","book4"}; 
	int lenBooks = 4;
	char* book = {"book2"};
	char* test = {"book2"};
	int result1 = cmp1(&book,&test);
	printf("测试cmp1方法的返回值是否为0: %d\n",result1);
	char* result2 = *(char **)search2(books,&book,lenBooks,sizeof(char*),cmp1);
	printf("在字符串数组中查找到的元素:result2 = %s\n",result2);
	if(strcmp(book,result2))
	{
		printf("存在该元素!\n");
	}else{
		printf("不存在该元素!\n");
	}
	
	
}
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