C# for循环①护栏长度 ②广场砖面积 ③判断闰年平年

 

 

// static void Main(string[] args)
        {

const double PI = 3.14;      

      const int BAR_UNIT_PRICE = 25;     

       const int BRICK_UNIT_PRICE = 85;     

       //输入       

     int a, b;           

Console.Write("请输入泳池半径：");         

   string s1 = Console.ReadLine();      

      a = Convert.ToInt32(s1);        

    Console.Write("请输入广场半径：");           

string s2 = Console.ReadLine();          

  b = Convert.ToInt32(s2);

            //运算        

    double l = 2 * PI * a;    //求泳池的周长      

      double area1 = PI * a * a;//泳池的面积。  

          double area2 = PI * b * b;//总面积。       

     double area = area2 - area1;//广场面积        

    double barPrice = l * BAR_UNIT_PRICE; //护栏的总造价       

     double brickPrice = area * BRICK_UNIT_PRICE;//广场的造价。

            //输出      

      Console.WriteLine("护栏的长度是" + l + "米，广场砖的总面积是" + area + "平米，总造价为" + (barPrice + brickPrice) + "元"); 

    }

    }
}

 

 

 

//第二题 判断一元二次方程根的情况。   

    

static void Main (string[] args)    

    {             int a, b, c;            //输入;             Console.Write("请输入系数a：");      

      a = Convert.ToInt32(Console.ReadLine());       

     Console.Write("请输入系数b：");       

     b = Convert.ToInt32(Console.ReadLine());         

   Console.Write("请输入系数c：");     

       c = Convert.ToInt32(Console.ReadLine());

            //运算输出       

     if (a == 0)        

    {             

   Console.WriteLine("不是一元二次方程");     

       }        

    else        

    {            

    int d = b * b - 4 * a * c;       

         if (d > 0)           

     {                

    Console.WriteLine("两个不等实根");         

       }              

  else if (d == 0)      

          {                 

   Console.WriteLine("两个相等实根");      

          }               

else               

{                

    Console.WriteLine("无实根");     

           }         

   }    

    }   

}

}

 

 

//第三题   输入一个年份判断是闰年，还是平年。  

      static void ccc(string[] args)     

   {       

     int year;           

//输入          

  Console.Write("请输入一个年份：");        

    year = Convert.ToInt32(Console.ReadLine());

  //运算           

//能被400整除；或能被4整除，但不能被100整除。       

     if ((year % 400 == 0) || (year % 4 == 0 && year % 100 != 0))        

    {             

   Console.WriteLine("是闰年");       

     }             else        

    {             

   Console.WriteLine("是平年");        

    }      

  } 

   }

}