using System;

public class Program

{

    //請把一個數字反轉過來

    public static string ReverseInteger(int number)

    {       

        string str = number.ToString();

        char[] newString= new char[str.Length];

        if(number>0){

        for(int i=0 ; i<str.Length ; i++){

            newString[str.Length -1 -i] = str[i];

        }

      }

        if(number<0){           

            newString[0] = str[0];

            for(int i=1 ; i<str.Length ; i++){          

            newString[str.Length-i] = str[i];

         }

        }

        return new string(newString) ;

    }

    //請找出一個陣列裡第二大的數字

    public static int SecondNumber(int[]array){

        int max=0;

        int second=0;

        for(int i=0;i<array.Length;i++){

         if(array[i]>max){

            max=array[i]; 

         }  

        }

        for(int i=0;i<array.Length;i++){

        if(array[i]> second && array[i]<max){

             second=array[i];

        }

       }

        return second;

    } 

    //請判斷數字是否能被 2,3,5 整除

    public static bool DivisibleNumber(int number)

    {

        if(number%2==0 ||number%3==0 || number%5==0 ){

         return true;

        }

        else{

         return false;

        }       

    }

    //給一個內含 0 到 n 的整數陣列，請找出這個陣列裡缺少的數字

    public static int FindMissingNumber(int[] array,int maxNumber){

      int allNumber=0;

      int origineAllNumber=0; 

      for(int i=0 ; i<array.Length ; i++){

           allNumber+=array[i];

      }

         origineAllNumber=((maxNumber+1)*maxNumber)/2;

         int missingNumber=origineAllNumber-allNumber;

         return missingNumber;

    }

    //給一個只有 0 和 1 的整數陣列，請找陣列裡連續出現最多次的 1 的次數

     public static int FindOne(int[] array){

        int max=0;

        int number=0;

        for(int i=0 ; i<array.Length ; i++){

            if(array[i]==1){

                number++;

                if(number>max){

                    max=number;

                }

            }

            else{

                number=0;

            }

        }

        return max;     

    }

    public static void Main()

    {

        Console.WriteLine("123 to " + ReverseInteger(123));

        Console.WriteLine("-123 to " + ReverseInteger(-123));

        int[] secondNumberArray={ 1,2,3,4,5,6,7};   

        int[] secondNumberArray2={ 9,3,6,12,5,7};   

        Console.WriteLine("The second largest number in 1,2,3,4,5,6,7 is"+ " " +  SecondNumber(secondNumberArray)); 

        Console.WriteLine("The second largest number in 9,3,6,12,5,7 is"+ " " +  SecondNumber(secondNumberArray2)); 

        int number1=15;

        int number2=12;

        int number3=17;

        int number4=1;

        Console.WriteLine(number1.ToString() + " " + "can be Divisible by 2, 3, 5 ? " + "" + DivisibleNumber(number1)); 

        Console.WriteLine(number2.ToString() + " " + "can be Divisible by 2, 3, 5 ? " + "" + DivisibleNumber(number2)); 

        Console.WriteLine(number3.ToString() + " " + "can be Divisible by 2, 3, 5 ? " + "" + DivisibleNumber(number3)); 

        Console.WriteLine(number4.ToString() + " " + "can be Divisible by 2, 3, 5 ? " + "" + DivisibleNumber(number4)); 

        int[] missingNumberArray={1,3,2,5,0} ;

        int[] missingNumberArray2={8,6,4,1,3,2,5,0 };

        Console.WriteLine("The missing number of 1,3,2,5,0 is" + " " + FindMissingNumber(missingNumberArray,5));

        Console.WriteLine("The missing number of 8,6,4,1,3,2,5,0 is" + " " + FindMissingNumber(missingNumberArray2,8));

​

        int[] findOneArray={1,1,1,1,0,0,1,1,1};

        int[] findOneArray2={1,1,0,0,1,1,1,1,1,1};

        Console.WriteLine("The number of consecutive occurrences of 1 in 1,1,1,1,0,0,1,1,1 is" + " " + FindOne(findOneArray));

        Console.WriteLine("The number of consecutive occurrences of 1 in 1,1,0,0,1,1,1,1,1,1 is" + " " + FindOne(findOneArray2));

    }

}