1.输出下列的格式的数字

/*

                       1,5

                    1,4   2,5

                  1,3  2,4  3,5

               1,2  2,3  3,4  4,5   

             

             */

    

int[] a = { 1, 2, 3, 4, 5 };            for (int i = 0; i < a.Length - 1; i++)            {                for (int j = 0; j < i + 1; j++)                {                    Console.WriteLine("(" + a[j] + "," + a[a.Length - 1 - i + j] + ")");                }            }

2./*一列数的规则如下: 1、1、2、3、5、8、13、21、34...... 求第30位数是多少， 用递归算法实现。*/

public static int DealNum(int i)        {            if (i <= 0)                return 0;            else if (i > 0 && i <= 2)                return 1;            else return DealNum(i - 1) + DealNum(i - 2);        }  调用： Console.write(DealNum(30));

3.//冒泡排序

public static int[] MaoPao(int[] Data)        {            int temp = 0;            int length = Data.Length - 1;            for (int i = 0; i < length; i++)            {                for (int j = length; j > i; j--)                {                    if (Data[j] > Data[j - 1])                    {                        temp = Data[j];                        Data[j] = Data[j - 1];                        Data[j - 1] = temp;                    }                }            }            return Data;        } 调用：int[] array = new int[] { 1, 4, 2, 3, 5 };        int[] newdata = MaoPao(array);            for (int i = 0; i < newdata.Length; i++)            {                Console.Write(newdata[i]);            }

4. /* 求一下表达式的值 1-2+3-4+......+m */

public static int DealNum(int m)   {    int sum =0;    bool flag=true;    for(int i=1;i<=m;i++)    {       if(flag)        sum+=i;           else         sum-=i;           flag=!flag;    }       return sum;    }