Question

编写一个接受整数n的程序，并以2n - 1行打印以下图片：

1       X
2      XXX
3     XXXXX
………………………………………………
2n  XXXXXXXXX  (2n-1 times)
………………………………………………
      XXXXX
       XXX

这是我拥有的代码，但它没有做到它应该做的事情，我做错了什么？我认为我需要对行做些什么，但我不确定。

import java.util.Scanner;
class a {
    public static void main(String[] args){
        Scanner input=new Scanner(System.in);
        System.out.println("enter a number: ");
        int n= input.nextInt();
        for(int i=0; i<n;i++){
            for (int j=0; j<=i; j++)
            System.out.print('X');
            System.out.println();

        }

        {
            System.out.println("enter a number: ");
            int c= input.nextInt();
            for(int i=0; i<c;i++){
                for (int j=0; j<=i; j++)
                    System.out.print('X');
                System.out.println();
            }

        }
    }
}

Answer 1

你的循环n次，而不是2n-1次。此外，您的打印j X，但您需要打印2n-1 X.

import java.util.Scanner;

public class a {
public static void main(String[] args){ 
    Scanner input=new Scanner(System.in);
    System.out.println("enter a number: ");
    int n= input.nextInt();
    int lines = 2*n-1;
    for(int i=1; i<=lines;i++) {
        int Xs = 2 * i - 1;
        int white = lines - Xs / 2;
        for(int j=0; j<white;j++) System.out.print(" ");
        for (int j=0; j<Xs; j++) System.out.print('X');
        for(int j=0; j<white;j++) System.out.print(" ");
        System.out.println();

    }
    for(int i=lines;i>=1;i--) {
        int Xs = 2*i-1;
        int white = lines - Xs / 2;
        for(int j=0; j<white;j++) System.out.print(" ");
        for(int j=0; j < Xs; j++) System.out.print("X");
        for(int j=0; j<white;j++) System.out.print(" ");
        System.out.println();
    }           
}
}

Answer 2

这是另一种解决方案

import java.util.Scanner;

public class a {
    public static void main(String[] args) {
        Scanner scn = new Scanner(System.in);
        int n = scn.nextInt();
        String accumulator = "";
        for (int i = 0; i < 2 * (n - 1) + 1; i++)accumulator += "x";
        String space = "";
        String res = accumulator;
        while (accumulator.length() > 2) {
            accumulator = accumulator.substring(2);
            space += " ";
            res = space + accumulator + "\n" + res + "\n" + space + accumulator;
        }
        System.out.println(res);
    }
}

我试图编写一个接受整数n的程序，然后用2n - 1行打印下面的图片：

2 个答案: