9.20 windows静态库和动态库的使用 函数可变参 递归使用 多线程查找

#include <stdio.h>
int main()
{
	double db[5] = {1.0,2.0,3.0,4.0,5.0};
	printf("%f\n", *((double *)(&db + 1) - 1)); // 结果输出5.0    
	return 0;
}

#include <stdio.h>
#include <stdlib.h>
int main()
{
	int *p = (int *)malloc(0); //内存分配0，也会分配成功。不过会发生内存冲突 
	printf("%p\n", p);
	return 0;
}

int sub(int a, int b)
{
	return a - b;
}

#include <stdio.h>
#pragma comment(lib,"my.lib")
int main()
{
	printf("%d\n", sub(13, 7));  //6
	return 0;
}

//导出函数，可以加载的时候调用
_declspec(dllexport)  int  add(int a, int b)
{
	return a + b;
}

#include <stdio.h>
#include <windows.h>
typedef int(*padd)(int a, int n);//定义函数指针
int main()
{
	HMODULE mydll = LoadLibraryA("my.dll");//装载模块
	if (mydll == NULL)
	{
		printf("装载模块失败\n");
	}
	else
	{
		padd myadd = (padd)GetProcAddress(mydll, "add");
		printf("%d\n", myadd(5, 8));
	}
	FreeLibrary(mydll);//卸载模块
	return 0;
}

#include <stdio.h>
#include <stdarg.h>
int add(int n, ...)
{
	int res = 0;
	va_list va;
	va_start(va, n);
	for (int i = 0; i < n; i++)
	{
		res += va_arg(va, int);
	}
	va_end(va);
	return res;
}
int main()
{
	printf("%d\n", add(3, 1, 2, 3));  //6
	return 0; 
}

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
void runcmd(int n, ...)
{
	va_list va;
	va_start(va, n);
	for (int i = 0; i < n; i++)
	{
		char *p = va_arg(va,char *);
		system(p);
	}
	va_end(va);
}
int main()
{
	runcmd(3,"calc","notepad","write");//函数 依次打开 计算器 记事本 写字板
	return 0;
}

#include <stdio.h>
#include <stdlib.h>
int main()
{
	for (int i = 0; i < 10;i++)
	{
		system("notepad");
	}
	return 0;
}

#include <stdio.h>
#include <stdlib.h>
int main()
{
	for (int i = 0; i < 10;i++)
	{
		system("start notepad");
	}
	return 0;
}

#include <stdio.h>
#include <stdlib.h>
struct STU
{
	int n;
	int a[5];
};
void change(struct STU s)
{
	s.n = 6;
	s.a[0] = 100; 
	printf("%d,%d\n", s.n, s.a[0]);    // 6 ， 100
}
int main()
{
	struct STU stu = { 5, {1,2,3,4,5} };
	printf("%d,%d\n", stu.n, stu.a[0]); // 5 ， 1
	change(stu);
	printf("%d,%d\n", stu.n, stu.a[0]); // 5 ， 1
	return 0;
}

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <windows.h>
int main()
{
	int i = 1;
	while (1)
	{
		char str[30] = { 0 };
		sprintf(str, "title 当前时间 %d 秒", i++);
		system(str);
		Sleep(1000);
	}
	return 0;
}

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <process.h>//多线程
#include <windows.h>
void time(void *p)
{
	int i = 0;
	while (1)
	{
		char str[100] = { 0 };
		sprintf(str, "title 当前时间%d秒", i);
		i++;
		system(str);//执行指令
		Sleep(1000);
	}
}
void gogo(void *p)
{
	int id = *(int *)p;
	for (int i = 1;; i++)
	{
		if (i > 2)
		{
			printf("\n%d  ,%d号线程结束", i, id);
			break;
		}
		Sleep(1000);
	}
	_endthread();//退出线程
}
void main()
{
	_beginthread(time, 0, NULL);//先执行窗口时间
	int a[5] = { 1, 2, 3, 4, 5 };
	for (int i = 0; i < 5; i++)
		_beginthread(gogo, 0, &a[i]);//异步
	getchar();
}

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <process.h>//多线程
#include <windows.h>
void time(void *p)
{
	int i = 0;
	while (1)
	{
		char str[100] = { 0 };
		sprintf(str, "title 当前时间%d秒", i);
		i++;
		system(str);//执行指令
		Sleep(1000);
	}
}
void gogo(void *p)
{
	int id = *(int *)p;
	for (int i = 1;; i++)
	{
		if (i > 2)
		{
			printf("\n%d  ,%d号线程结束", i, id);
			break;
		}
		Sleep(1000);
	}
	_endthread();//退出线程
}
void main()
{
	_beginthread(time, 0, NULL);//先执行窗口时间
	int a[5] = { 1, 2, 3, 4, 5 };
	for (int i = 0; i < 5; i++)
	{
		HANDLE hd = _beginthread(gogo, 0, &a[i]);
		WaitForSingleObject(hd, INFINITE);//同步
	}
	getchar();
}

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <process.h>
int flag = 0;//0为没有找到，1为找到
struct MyStruct
{
	int *pfindfirst;//查找的首地址
	int length;//查找的长度
	int num;//要查找的数据
	int id;//线程的编号
	int * pfind;//找到的地址
};
void find(void *p)
{
	struct MyStruct *pstruct = p;//指针类型转换
	//遍历内存
	for (int *px = pstruct->pfindfirst; px < pstruct->pfindfirst + pstruct->length; px++)
	{
		if (flag == 1)
		{
			printf("线程%d没有找到,其他线程已经找到\n", pstruct->id);
			return;
		}
		if (*px == pstruct->num)//对比是否相等
		{
			pstruct->pfind = px;//赋值
			printf("%d号线程找到%d,%p\n", pstruct->id, *px, px);//找到提示
			flag = 1;
			return;//返回
		}
	}
	printf("线程%d没有找到\n", pstruct->id);
}
void main()
{
	int a[1000] = { 0 };//多线程顺序查找
	for (int i = 0; i < 1000; i++)
	{
		a[i] = i;//赋值初始化数组
	}
	int threadnum;
	int findnum;
	printf("请输入需要多少个线程\n");
	scanf("%d", &threadnum);
	printf("请输入要查找的数据\n");
	scanf("%d", &findnum);
	//动态开辟结构体数组
	if (1000 % threadnum != 0)
	{
		struct MyStruct *pstruct = malloc(sizeof(struct MyStruct)*threadnum);
		for (int i = 0; i < threadnum - 1; i++)
		{
			pstruct[i].pfindfirst = a + i * (1000 / (threadnum - 1));//确定查找的地址
			pstruct[i].length = (1000 / (threadnum - 1));//查找的长度
			pstruct[i].id = i;//编号
			pstruct[i].num = findnum;//查找的数据
			pstruct[i].pfind = NULL;
			_beginthread(find, 0, &pstruct[i]);
		}
		{
			int i = threadnum - 1;//处理最后一个线程
			pstruct[i].pfindfirst = a + (1000 / (threadnum - 1))*(threadnum - 1);//确定查找的地址
			pstruct[i].length = 1000 - (1000 / (threadnum - 1))*(threadnum - 1);//查找的长度
			pstruct[i].id = i;//编号
			pstruct[i].num = findnum;//查找的数据
			pstruct[i].pfind = NULL;
			_beginthread(find, 0, &pstruct[i]);
		}
	}
	system("pause");
}