[c/c++] programming之路（11）、顺序分支

一、模块化设计

 #include<stdio.h>
 #include<stdlib.h>
 #include<windows.h>

 void openbaidu(){
     ShellExecuteA(,"open","https://www.baidu.com",,,);
 }
 void closebaidu(){
     system("taskkill /f /im 360se.exe");
 }
 void clickbaidu(){
     /*SetWindowPos
         MOUSE_EVENT*/
     SetCursorPos(,);//设置鼠标位置
     mouse_event(MOUSEEVENTF_LEFTDOWN,,,,);//鼠标左键按下
     mouse_event(MOUSEEVENTF_LEFTUP,,,,);//鼠标左键抬起
     //mouse_event(MOUSEEVENTF_LEFTDOWN,0,0,0,0);//鼠标左键按下
     //mouse_event(MOUSEEVENTF_LEFTUP,0,0,0,0);//鼠标左键抬起
 }

 //模块化设计：1.打开浏览器（百度）    2.打开网页    3.关闭浏览器
 void main(){
     while(){
         openbaidu();
         Sleep();//休眠5秒钟
         clickbaidu();
         Sleep();
         closebaidu();
         Sleep();
     }
 }

二、顺序结构

打开屏幕左上角的计算器，等待2秒，关闭计算器

 #include<stdio.h>
 #include<stdlib.h>
 #include<windows.h>

 void main(){
     SetCursorPos(,);
     Sleep();
     //双击左键
     mouse_event(MOUSEEVENTF_LEFTDOWN,,,,);//鼠标左键按下
     mouse_event(MOUSEEVENTF_LEFTUP,,,,);//鼠标左键抬起
     mouse_event(MOUSEEVENTF_LEFTDOWN,,,,);
     mouse_event(MOUSEEVENTF_LEFTUP,,,,);
     Sleep();
     system("taskkill /f /im calc.exe");
     system("pause");
 }

三、分支结构

 #include<stdio.h>
 #include<stdlib.h>
 #include<windows.h>

 void main0(){
     if(-){//0不执行，非0执行块语句
         //0隐藏  1正常  3最大化  6最小化
         ShellExecuteA(,"open","http://www.taobao.com",,,);
     }
     printf("hello taobao");
     system("pause");
 }

 void main1(){
     int i=;
     //每7秒打开百度，每11秒打开淘宝
     while(){
         if(i%==){
             ShellExecuteA(,"open","http://www.baidu.com",,,);
         }
         if(i%==){
             ShellExecuteA(,"open","http://www.taobao.com",,,);
         }
         if(i%==){
             system("taskkill /f /im 360se.exe");
         }

         Sleep();
         i++;
         printf("第%d秒\n",i);
     }
 }

 void main(){
     int num;
     scanf("%d",&num);
     if(num){//判断num是否为0
         printf("gogogogo");
     }
     system("pause");
 }

三个数，按从大到小排列

 #include<stdio.h>
 #include<stdlib.h>

 void main(){
     //从大到小，a最大,c最小
     double a,b,c,temp;
     //scanf("%f%f%f",&a,&b,&c);
     scanf("%lf%lf%lf",&a,&b,&c);//double类型数据，需要用 %lf 格式符
     printf("a=%f,b=%f,c=%f",a,b,c);
     if(a<b){
         temp=a;
         a=b;
         b=temp;
     }
     if(a<c){
         temp=a;
         a=c;
         c=temp;
     }
     if(b<c){
         temp=b;
         b=c;
         c=temp;
     }
     printf("\n%f,%f,%f",a,b,c);
     system("pause");
 }

输出绝对值大的数

 #include<stdio.h>
 #include<stdlib.h>

 void main(){
     int x,y;
     unsigned int x1,y1;
     scanf("%d%d",&x,&y);
     if(x>=){
         x1=x;
     }else
     {
         x1=-*x;
     }
     if(y>=)    y1=y;
     else
     {
         y1=-*y;
     }
     printf("%d",x1>y1?x:y);

     system("pause");
 }

四、逻辑嵌套（求解一元二次方程）

 #include<stdio.h>
 #include<stdlib.h>
 #include<math.h>
 void main(){
     int a,b,c;
     double delt;
     printf("请输入a，b，c的值：");
     scanf("%d%d%d",&a,&b,&c);
     printf("%d*x*x+%d*x+%d=0\n",a,b,c);
     //逻辑嵌套
     if(a==){
         if(b==){
             if(c==){
                 printf("x为任意解");
             }else
             {
                 printf("无解");
             }
         }else{
             printf("x= %f",-1.0*c/b);//一元一次方程
         }
     }else{
         delt=b*b-*a*c;
         if(delt<){
             printf("方程只有两个虚根：x1=%f+%fi,x2=%f-%fi",-1.0*b//a,sqrt(-delt)//a,-1.0*b//a,sqrt(-delt)//a);
         }else{
             printf("方程有两个实根：x1=%f,x2=%f",(-b+sqrt(delt))//a,(-b-sqrt(delt))//a);
         }
     }
     system("pause");
 }

四、switch语句

 #include<stdio.h>
 #include<stdlib.h>
 void main(){
     int num;
     scanf("%d",&num);
     printf("%d",num);
     switch (num)
     {
     case ://几个case分支没有顺序区别
         printf("司令");
         break;
     case :
         printf("军长");
         break;
     case :
         printf("师长");
         break;
     case :
         printf("旅长");
         break;
     case :
         printf("团长");
         break;
     case :
         printf("营长");
         break;
     case :
         printf("连长");
         break;
     case :
         printf("排长");
         break;
     case :
         printf("班长");
         break;
     case :
         printf("小组长");
         break;
     case :
     case -://共用语句
         printf("大兵阿飞");
         break;
     default://switch语句中可以不含default分支
         printf("输入错误");
         break;
     }
     system("pause");
 }