嵌套循环以在矩形框架内打印

Question

我正在尝试在矩形框内打印一棵树，虽然我的方法完全有效，但我无法弄清楚如何相互实现它们。

我试图在框架方法中打印树方法而不是空格，但它不起作用，现在我不知道该怎么做。

我目前正在学习 java，所以它对我来说仍然是一个全新的领域。

import java.util.Scanner;

public class Weihnachtsbaum {
    public static void main(String[] args)
    {

        Scanner scan = new Scanner(System.in);
        System.out.print("Enter a number between 1 and 20: ");
        int height = scan.nextInt();

        while((height < 1) || (height > 20))
        {
            System.out.println("Number not inside parameters!");
            System.out.print("Enter a number between 1 and 20: ");
            height = scan.nextInt();
        }
        
        //this is only to test that the outputs are right
        tree(height);
        System.out.println();
        frame(height);
        
    }

    static void tree(int height)
    {
        for(int i = 1;i <=height; i++)
        {
        //printing star
            if(i == 1)
            {
                for (int j = height - 2; j > 0; j--)
                {
                    System.out.print(" ");
                }

                for (int k = 1; k > 0; k--)
                {
                    System.out.println(">()<");
                }
            }
            //printing spaces
            for (int space = 1;space <= height - i; space++)
            {
                System.out.print(" ");
            }
            //branches
            for (int branch = 1; branch <= i; branch++)
            {
                
                System.out.print("/\\");
            }
            //next line
            System.out.println();

            //lower part of tree
            if(i == height)
            {
                for(int j = (height-1);j > 0;j--)
                {
                    System.out.print(" ");
                }
                for(int k = 2;k > 0;k--)
                {
                    
                    System.out.print("|");
                }

            }
        }
    }

    static void frame(int height)
    {

    for(int rows = 0; rows <= height+4; rows++)
    {
        for(int columns =  0; columns <= height*2+4; columns++)
        {
            if((rows == 0 && columns == 0) || (rows == height+4 && columns==0) || (columns == height*2+4 && rows == 0) || (rows == height+4 && columns == height*2+4))
            { 
            System.out.print("+");
            }
            else if( rows == 0 || rows == height+4)
            {
                System.out.print("-");
            }
            else if(columns == 0 || columns == height*2+4)
            {
                System.out.print("|");
            }
            else
            {
                System.out.print(" ");
            }
        }
        System.out.println();
    }
    }
}

Answer 1

我想我可能已经做到了，即使代码不是最好看的，但这应该能做到，感谢您的帮助。 如果你能帮助我最小化代码，我将不胜感激，但如果不能，这应该足以获得批准，因为它有效。

import java.util.Scanner;

public class weihnachtsbaum2 {
    public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        System.out.print("Bitte eine Zahl zwischen 1 und 20 eingeben: ");
        int height = scan.nextInt();

        while ((height < 1) || (height > 20))
        {
            System.out.println("Nicht gültige Zahl! ");
            System.out.print("Bite eine gültige Zahl zwischen 1 und 20 eingeben: ");
            height = scan.nextInt();
        }

        topFrame(height);
        middlePart(height);
        bottomPart(height);

    }

    static void topFrame(int height)
    {
        //Top of Frame
        for (int rows = 0; rows <= height; rows++)
        {
            for (int columns = 0; columns <= height+2; columns++)
            {
                if((rows == 0 && columns == 0) || (rows == height && columns==height+2))
                {
                    System.out.print("+");
                }
                else if( rows == 0 || rows == height)
                {
                    System.out.print("-");
                }
            }
            if(rows == height)
            {
                System.out.println();
            }
        }
    }

    static void middlePart(int height)
    {
        for (int rows = 0; rows <= height-1; rows++)
        {   //spalten
            //printing star
            if(rows == 0)
            {
                System.out.print("|");
                for (int j = height; j > 0; j--)
                {

                    System.out.print(" ");
                }

                for (int k = 1; k > 0; k--)
                {
                    System.out.print(">()<");
                }
                for(int x = 0; x <= height-1; x++)
                {
                    System.out.print(" ");
                }
                System.out.print("|\n");

            }
            if(rows >= 0)
            {
                System.out.print("|");
            }
            for (int spaceLeft = 0;spaceLeft <= height - rows; spaceLeft++)
            {
                System.out.print(" ");
            }
            //branches
            for (int branch = 0; branch <= rows; branch++)
            {
                System.out.print("/\\");

            }
            for (int spaceRight = 0;spaceRight <= height - rows; spaceRight++)
            {
                System.out.print(" ");

            }
            System.out.print("|");
            System.out.println();
            if(rows == height-1)
            {
                System.out.print("|");
                for(int j = (height);j >= 0;j--)
                {
                    System.out.print(" ");
                }
                for(int k = 2;k > 0;k--)
                {

                    System.out.print("|");
                }
                for (int spaceRight = 0;spaceRight <= height; spaceRight++)
                {
                    System.out.print(" ");

                }
                System.out.print("|");
            }
        }
        System.out.println();
    }

    static void bottomPart(int height)
    {
        //bottom of Frame
        for (int rows = 0; rows <= height; rows++)
        {   //spalten
            for (int columns = 0; columns <= height+2; columns++)
            {
                if((rows == 0 && columns == 0) || (rows == height && columns==height+2))
                {
                    System.out.print("+");
                }
                else if( rows == 0 || rows == height)
                {
                    System.out.print("-");
                }
            }
            if(rows == height)
            {
                System.out.println();
            }
        }
    }
}

Answer 2

使用循环的另一种方法是使用String.repeat语句。 您也可以使用相同的方法打印顶部和底部边框。

public class Weihnachtsbaum2 {
    public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        System.out.print("Bitte eine Zahl zwischen 1 und 20 eingeben: ");
        int height = scan.nextInt();

        while ((height < 1) || (height > 20)) {
            System.out.println("Nicht gültige Zahl! ");
            System.out.print(
                    "Bite eine gültige Zahl zwischen 1 und 20 eingeben: ");
            height = scan.nextInt();
        }

        topAndBottom(height);
        middlePart(height);
        topAndBottom(height);

    }

    static void topAndBottom(int height) {
        // Top of Frame
        System.out.println("+" + "-".repeat(2 * (height+2)) + "+");

    }

    static void middlePart(int height) {
        String spaces = " ".repeat(height);
        String leftEnds = "|" + spaces;
        String rightEnds = spaces + "|";
        
        System.out.println(leftEnds + ">()<" + rightEnds);
        
        for (int row = 1; row <= height; row++) {
            spaces = " ".repeat(height-row+1);
            String left = "| " + spaces;
            String right = spaces + " |";
            String center = "/\\".repeat(row);
            
            System.out.println(left + center + right);
        }
        System.out.println(leftEnds + " || " + rightEnds);
    }
}

Answer 3

也许是这样的（不是最干净的代码，但可以工作）。 请注意一些更改 - 我已经对height进行了硬编码，但您可以轻松地使用现有代码从用户那里获取输入。 此外，该程序不会打印星号 - 将其作为熟悉代码的练习:)

public class MyTree {
    public static void main(String[] args) {
        // You can reuse your code to accept input here
        int height = 12;
        printTree(height);
    }

    public static void printTree(int height){
        printTop(height); // Prints the top row of frame
        for(int i=0; i<height; i++){
            printRow(i+1, height); 
        }
        printTrunk(height); // Prints the tree stock/trunk
        printBottom(height); // Prints the bottom row of the frame
    }


    public static void printTop(int height){
        System.out.print("+");
        for(int i=0; i < (height*2) + 4; i++){
            System.out.print("-");
        }
        System.out.println("+");
    }

    private static void printBottom(int height){
        printTop(height);
    }

    private static void printSpaces(int spaces) {
        for(int i=0; i<spaces; i++){
            System.out.print(" ");
        }
    }

    private static void printRow(int rowNum, int height){
        int spaces = (height - rowNum) + 3;
        System.out.print("|");
        printSpaces(spaces-1);

        for(int i=0; i<rowNum; i++){
            System.out.print("/\\");
        }

        printSpaces(spaces-1);
        System.out.print("|");
        System.out.println("");
    }

    private static void printTrunk(int height) {
        System.out.print("|");
        printSpaces(height + 1);
        System.out.print("||");
        printSpaces(height + 1);
        System.out.print("|");
        System.out.println("");
    }
}

为输入 10 打印树（注意没有星号），如下所示：

随意根据自己的喜好改进代码（那里有很多scope）