#region 练习题一
int[] array = new int[100];
for (int i = 0; i < array.Length; i++)
{
    array[i] = i;
    Console.Write(array[i] + " ");
}
Console.ReadKey();
Console.Clear();
#endregion


#region 练习题二
int[] array2 = new int[100];
for (int i = 0; i < array2.Length; i++)
{
    array2[i] = array[i]*2;
    Console.Write(array2[i] + " ");
}
Console.ReadKey();
Console.Clear();
#endregion


#region 练习题三
int[] array3 = new int[100];
Random r = new Random();
for (int i = 0; i < array3.Length; i++)
{
    array3[i] = r.Next(0,101);
    Console.Write(array3[i] + " ");
}
Console.ReadKey();
Console.Clear();
#endregion


#region 练习题四
int[] array4 = new int[100];
int max=0, min=100, sum=0, avg=0;
for (int i = 0; i < array4.Length; i++)
{
    array4[i] = r.Next(0, 101);
    if(max < array4[i])
    {
        max = array4[i];
    }
    if(min > array4[i])
    {
        min = array4[i];
    }
    sum += array4[i];
    avg = sum / array4.Length;
    Console.Write(array4[i] + " ");
}
Console.WriteLine();
Console.WriteLine($"最大值为：{max}");
Console.WriteLine($"最小值为：{min}");
Console.WriteLine($"总和为：{sum}");
Console.WriteLine($"平均值为：{avg}");
Console.ReadKey();
Console.Clear();
#endregion


#region 练习题五
int[] array5 = new int[10];
for (int i = 0; i < array5.Length; i++)
{
    array5[i] = r.Next(0, 101);
    Console.Write(array5[i] + " ");
}
//反转
int temp;
for (int i = 0; i < array5.Length / 2; i++)
{
    temp = array5[i];
    array5[i] = array5[array5.Length - 1 - i];
    array5[array5.Length - 1 - i] = temp;
    
}
Console.WriteLine();
Console.WriteLine("反转后：");
for (int i = 0; i < array5.Length; i++)
{
    Console.Write(array5[i] + " ");
}
Console.WriteLine();
Console.WriteLine("反打反转：");
for (int i = array5.Length - 1; i >= 0; i--)
{
    Console.Write(array5[i] + " ");
}
Console.ReadKey();
Console.Clear();
#endregion


#region 练习题六
int[] array6 = new int[10];
for (int i = 0; i < array6.Length; i++)
{
    array6[i] = r.Next(-10, 11);
    Console.Write(array6[i] + " ");
}
for (int i = 0;i < array6.Length; i++)
{
    if (array6[i] < 0)
    {
        array6[i] -= 1;
    }
    else if (array6[i] > 0)
    {
        array6[i] += 1;
    }
}
Console.WriteLine();
Console.WriteLine("处理后：");
for (int i = 0; i < array6.Length; i++)
{
    Console.Write(array6[i] + " ");
}
Console.ReadKey();
Console.Clear();
#endregion


#region 练习题七
int[] array7 = new int[10];
try
{
    for (int i = 0; i < array7.Length; i++)
    {
        Console.Write($"请输入第{i + 1}位同学的成绩：");
        array7[i] = int.Parse(Console.ReadLine());

    }
}
catch
{
    Console.WriteLine("输入错误，请输入数字！");
    return;
}
max = array7[0];
min = array7[0];
sum = 0;
avg = 0;
for (int i = 0; i < array7.Length; i++)
{
    if (max < array7[i])
    {
        max = array7[i];
    }
    if (min > array7[i])
    {
        min = array7[i];
    }
    sum += array7[i];
}
avg = sum / array7.Length;
Console.WriteLine($"成绩最高成绩为{max}");
Console.WriteLine($"成绩最低成绩为{min}");
Console.WriteLine($"成绩总和成绩为{sum}");
Console.WriteLine($"平均成绩成绩为{avg}");
for (int i = 0; i < array7.Length; i++)
{
    if (array7[i] >= 60)
    {
        Console.WriteLine($"第{i + 1}位同学成绩为：{array7[i]}，成绩合格");
    }
    else
    {
        Console.WriteLine($"第{i + 1}位同学成绩为：{array7[i]}，成绩不合格");
    }
}
#endregion


#region 练习题八
string[] array8 = new string[25];
for (int i = 0; i < array8.Length; i++)
{
    //if (i % 2 == 0)
    //{
    //    array8[i] = "■";
    //}
    //else
    //{
    //    array8[i] = "□";
    //}
    array8[i] = i % 2 == 0 ? "■" : "□";//无敌
    //打印
    Console.Write(array8[i]);
    if ((i + 1) % 5 == 0)
    {
        Console.WriteLine();
    }
}
#endregion