<C#任务导引教程>练习一

//1,定位显示ASCI码值为30到119的字符
using System;
class Program
{
    static void Main()
    {
        int i, n = 0;
        for (i = 30; i <= 119; i++)
        {
            if (n % 10 == 0 && n > 0)
                Console.WriteLine();
                Console.Write("{0:D3}:{1}  ", i, (char)i);
                n++;     
        }
        Console.WriteLine();
    }
}

//2，按左下方为三角形格式输出九九乘法表
using System;
class Program
{
    static void Main()
    {
        int m, n;
        Console.Write("   *");
        for (m = 1; m <= 9; m++)
            Console.Write("{0,4}", m);
        Console.WriteLine();
        for (m = 1; m <= 9; m++)
        {
            Console.Write("{0,4}", m);
            for (n = 1; n <= m; n++)
                Console.Write("{0,4}", m * n);
            Console.WriteLine();
        }
    }
}

//2.1，编程输出倒三角图案
using System;
class Program
{
    static void Main()
    {
        int i, j, k;
        for (i = 1; i <= 4; i++)
        {
            for (j = 1; j < i; j++)
                Console.Write(" ");
            for (k = 1; k <= 9 - 2 * i; k++)
                Console.Write("*");
            Console.WriteLine();
        }
    }
}

//3，编程输出1-100的3的倍数
using System;
class Program
{
    static void Main()
    {
        int i, n = 0;
        for (i = 1; i < 100; i++)
        {
            if (i % 3 != 0)
                continue;
            if (n % 10 == 0 && n > 0)
                Console.WriteLine();
            n++;
            Console.Write("{0,3}", i);
        }
        Console.WriteLine();
    }
}

//4，输入5个整数，并显示正整数，读到负整数时做出相应处理
using System;
class MainClass
{
    static void Main()
    {
        int i;
        for (i = 1; i <= 5; i++)
        {
            Console.Write("请输入第{0}个数:", i);
            string x = Console.ReadLine();
            int n = int.Parse(x);
            if (n < 0)
                break;
            Console.WriteLine("n={0}", n);
        }
        Console.WriteLine("该数是负数!");
    }
}

//5，输入5个整数，并显示正整数，读到负整数时做出相应处理
using System;
class MainClass
{
    static void Main()
    {
        int i;
        for (i = 1; i <= 5; i++)
        {
            Console.Write("请输入第{0}个数:", i);
            string x = Console.ReadLine();
            int n = int.Parse(x);
            if (n < 0)
                continue;
            Console.WriteLine("n={0}", n);
        }
        Console.WriteLine("该数是负数!");
    }
}