java - 文本输出居中时出现问题

Question

所以，我有一个作业要求我根据用户输入打印一些形状(树)。我正确地获得了所有形状，但还有第二个形状也应该打印，即底部正方形(树的底部)，第二个正方形应该以顶部正方形(实际的树)为中心。

这是到目前为止的代码:

public class TreeStructures {

    public static void main(String[] args) {
        Scanner scnr = new Scanner(System.in);

        int height = 0;
        int weidth = 0;
        int weidth2 = 0;

        //Introduction
        System.out.println("Tree Structures");
        System.out.println("---------------\n");
        System.out.println("This program prints two tree like structures! ");
        System.out.println("A \"Flat\" tree and a \"Christmas\" tree.");
        System.out.println("You choose how big the trees will be.\n");
        System.out.println("By Daniel Sousa (A00433806)\n");

        //User input
        System.out.print("How tall should the top of the tree be? ");
        height = scnr.nextInt();
        System.out.println();

        //Input check
        if (height > 4 && height < 21) {            
            System.out.println("Flat Tree:");

            //Top Square
            for (int i = 1; i <= height; i++) {
                System.out.println(" ");
                for (int j = 0; j <= (height*2) - 2; j++) {
                    System.out.print("*");
                    weidth = j;
                }
            }
            //Bottom Square
            for (int i = 1; i <= (height/5) + 1; i++) {
                System.out.println(" ");
                for (int k = 1; k <= (weidth - weidth2)/2; k++) {
                System.out.print(" ");
                }
                for (int j = 0; j <= weidth/3; j++) {
                    System.out.print("<");
                    weidth2 = j;
                }

            }
        }

        //Invalid Input
        else {
            System.out.println("That's not a valid size.  "
                    + "I can only do trees from 5 to 20.\n");
            System.out.println("Quitting now.\n");
            System.out.print("Press enter...");
            scnr.nextLine();
            scnr.nextLine();
        }
    }
}
\\\

这是应该创建第二个矩形并将其居中的特定代码块:

for (int i = 1; i <= (height/5) + 1; i++) {
            System.out.println(" ");
            for (int k = 1; k <= (weidth - weidth2)/2; k++) {
            System.out.print(" ");
            }
            for (int j = 0; j <= weidth/3; j++) {
                System.out.print("<");
                weidth2 = j;
            }

        }

作为输出，它按预期创建第二个矩形，甚至也正确缩进，但缩进的第一行生成了太多空格，原因我无法解释。

输出示例(将“X”替换为空格):

\\\
Tree Structures
---------------

This program prints two tree like structures! 
A "Flat" tree and a "Christmas" tree.
You choose how big the trees will be.

By Daniel Sousa (A00433806)

How tall should the top of the tree be? 19

Flat Tree:

************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
************************************* 
XXXXXXXXXXXXXXXXXX<<<<<<<<<<<<< //!-!-!-! <-problematic line
XXXXXXXXXXXX<<<<<<<<<<<<< 
XXXXXXXXXXXX<<<<<<<<<<<<< 
XXXXXXXXXXXX<<<<<<<<<<<<

我的问题是:如何使第二个矩形的第一行缩进(“X”)与其他行一样多。或者更好的是，如何使第二个矩形与第一个矩形的中间对齐？

谢谢!

Answer 1

你似乎用 for 循环使它变得过于复杂，使用 2 个循环(你移动的每个轴 1 个)并用简单的方法来决定是否应该打印某些东西不是更容易吗？像这样:

for (int i = 1; i <= (height/5) + 1; i++) {
    System.out.println(" ");
    for (int k = 1; k <= 2*weidth/3; k++) {
        if (k < weidth/3){
            System.out.print(" ");
        } else {
            System.out.print("<");
        }
    }
}