Question

看看这个问题：编写一个打印9个版权符号的三角形的程序©

控制台应使用这些©符号打印一个简单的三角形。三角形必须是空的，没有填充©个东西。

我更改了控制台字符编码：

 Console.OutputEncoding = Encoding.UTF8;

所以©正确打印。我也改变了字体。

我一直试图通过使用 for loop 来找出绘制三角形的方法，但我的新手知识显然仍然不足以完成这类任务。

你能否给我一些关于如何使用 for loop 绘制三角形的提示/提示？

顺便说一下，我发现这个问题解决了这个问题：

Console.OutputEncoding = Encoding.UTF8;
        char copyRight = '\u00A9';
        Console.WriteLine("{0,4}\n{0,3}{0,2}\n{0,2}{0,4}\n{0}{0,2}{0,2}{0,2}", copyRight);

Answer 1

你能否给我一些关于如何用for循环绘制三角形的提示/提示？

不确定。开始于：您是否可以编写一个您理解的 绘制三角形而不使用任何循环的程序？

完成上述操作后，您是否可以使用更简单的循环编写该程序，例如while？

如果没有，请在解决while之前了解for的工作原理。您应该能够清楚地回答问题＆＃34; if(condition) statement和while(condition) statement形式的代码之间的区别是什么？＆＃34;

完成上述操作后，您是否可以将使用while编写的正确程序转换为使用for的等效程序？ while和for之间存在非常明确的关系。

Answer 2

这是一个简单的例子。它看起来比它更可怕。

©©©©©©©©©
©©©© ©©©©
©©©   ©©©
©©     ©©
©       ©
©©©©©©©©©

输出：

static void Main(string[] args)
{
    Console.OutputEncoding = Encoding.UTF8;
    Render(Draw('\u00A9', 4));
    Render(Draw('\u00A9', 8));
    Render(Draw('\u00A9', 16));
}

static char[,] Draw(char sym, int height)
{
    int width = (height * 2) - 1;
    char[,] map = new char[height, width];
    int x = width - 1;
    int y = height - 1;

    for (int i = 0; i < height; i++)
    {
        map[y, i * 2] = sym;

        if (i != 0)
        {
            map[y - i, i] = sym;
            map[y - i, x - i] = sym;
        }
    }

    return map;
}

static void Render(char[,] map)
{
    int width = map.GetLength(1);
    int height = map.GetLength(0);

    for (int i = 0; i < height; i++)
    {
        if (i != 0)
        {
            Console.WriteLine();
        }

        for (int j = 0; j < width; j++)
        {
            char c = map[i, j];

            Console.Write(c == '\0' ? ' ' : c);
        }
    }

    Console.WriteLine();
}

9个符号的替代版本：

   ©
  © ©
 ©   ©
© © © ©
       ©
      © ©
     ©   ©
    ©     ©
   ©       ©
  ©         ©
 ©           ©
© © © © © © © ©
               ©
              © ©
             ©   ©
            ©     ©
           ©       ©
          ©         ©
         ©           ©
        ©             ©
       ©               ©
      ©                 ©
     ©                   ©
    ©                     ©
   ©                       ©
  ©                         ©
 ©                           ©
© © © © © © © © © © © © © © © ©

输出：

import java.util.Scanner;

public class RationalDriver
{
  private static Scanner in = new Scanner(System.in);
  private static char choice;
  private static String input;



  public static void main(String[] args)
  {
    printHeading();
    Rational first = new Rational();
    numberOne(first);
    Rational second = new Rational();
    numberTwo(second);
    menu(first, second);
  }

  public static void menu(Rational first, Rational second)
  {
    try{
    displayMenu();
    getValue(choice);

    if(choice == '1')
    {
      System.out.println("\n" + first + " + " + second + " equals ");
      first.add(second);
      System.out.println(first);
    }

    else if(choice == '2')
    {
      System.out.println("\n" + first + " - " + second + " equals ");
      first.subtract(second);
      System.out.println(first);
    }

    else if(choice == '3')
    {
      System.out.println("\n" + first + " * " + second + " equals ");
      first.multiply(second);
      System.out.println(first);
    }

    else if(choice == '4')
    {
      System.out.println("\n" + first + " / " + second + " equals ");
      first.divide(second);
      System.out.println(first);
    }

    else if(choice == '5')
    {
      System.out.println("\nAre " + first + " and " + second + " equal?");
      if(first.equals(second))
      {
        System.out.println("\nYes!");
      }
    }

    else if(choice == '6')
    {
      System.out.println("Please enter a new rational number: ");
      numberOne(first);
    }

    else if(choice == '7')
    {
      System.out.println("Please enter a new rational number: ");
      numberTwo(second);
    }

    else if(choice == '8')
    {
      System.out.println("You chose to exit.");
      System.exit(0);
    }
    else
    {
      System.out.println("You did not choose a valid entry.");
    }
    }
    catch (Exception e) { e.printStackTrace(); }
  }

  private static void printHeading()  // printHeading method
  {
    System.out.println("Oliver, James");
    System.out.println("CSC201-02PR");
    System.out.println("Dr. Java");
    System.out.println("Project 7");
    System.out.println("Rational Number");
    System.out.println();
  }

  private static void displayMenu()
  {
    System.out.println("Enter the corresponding number for the desired action:");
    System.out.println("1. Addition");
    System.out.println("2. Subtraction");
    System.out.println("3. Multiplication");
    System.out.println("4. Division");
    System.out.println("5. Test for Equality");
    System.out.println("6. Change 1st Rational Number");
    System.out.println("7. Change 2nd Rational Number");
    System.out.println("8. Exit");
  }

  public static char getValue(char choice)
  {
    System.out.println("\nPlease enter your menu option (1 - 8):");
    choice = in.next().charAt(0);
    return choice;
  }

  public static void numberOne(Rational first)
  {
    int numer = 0;
    int denom = 1;
    boolean breaker = false;
    while(!breaker)
    {
      System.out.println("Please enter your first numerator:");
      input = in.next();
      numer = Integer.parseInt(input);
      System.out.println("Please enter your first denominator:");
      input = in.next();
      denom = Integer.parseInt(input);
      if(denom == 0)
      {
        System.out.println("Denominator cannot be undefined.");
        denom = in.nextInt();
      }
      else
        breaker = true;
    }

    first.setNumer(numer);
    first.setDenom(denom);
    first.normalize();
    System.out.println("Your rational number is: " + first + "\n");
  }

  public static void numberTwo(Rational second)
  {
    int numer = 0;
    int denom = 1;
    boolean breaker = false;
    while(!breaker)
    {
      System.out.println("Please enter your second numerator:");
      input = in.next();
      numer = Integer.parseInt(input);
      System.out.println("Please enter your second denominator:");
      input = in.next();
      denom = Integer.parseInt(input);
      if(denom == 0)
      {
        System.out.println("Denominator cannot be undefined.");
        denom = in.nextInt();
      }
      else
        breaker = true;
    }

    second.setNumer(numer);
    second.setDenom(denom);
    second.normalize();
    System.out.println("\nYour rational number is: " + second + "\n");
  }

}

Answer 3

我一直想知道没有人使用PadLeft和PadRight：

<?php
$query = $db->prepare("SELECT email FROM `users` WHERE `email` = :email");
$query->execute(array(
':email'    =>  $email
));
$count = $query->rowCount();
echo $count;
?>

阅读代码中的注释，并使用此方法稍微玩一下：）

使用©符号绘制三角形

3 个答案: