java - 在Java中创建数字矩阵

Question

我正在尝试编写一个程序，提示用户输入 1 到 9 之间的数字，并创建一个 x × x 的矩阵，其中 x 是给定的数字。它应该产生从 1 到 x^2 的随机数来填充矩阵。我已经解决了，如果我输入“5”，我会得到一行有 5 个随机数字的行，然后是四行，每行只有一个数字。我错过了什么？

import java.util.Scanner;
import java.util.Random;
public class MatrixFiller
{
  public static void main(String[] args)
  {
    //Getting input from the user
    Scanner input = new Scanner(System.in);
    System.out.print("Size of Matrix(a number between 1 and 9): ");
    int matrixn = input.nextInt();
    input.close();
    //max is the largest possible number that can be calculated
    //with the given number squared.
    int max = (matrixn * matrixn);
    //Counters for building the matrix
    int i = 0;
    int j = 0;
    //Will create a line with x numbers on it but then produces
    //x lines with only one number. If given 5 it produces a
    //line with 5 numbers then four more lines with one number
    //each.
        do {
          do {
            Random rand = new Random();
            int mout = rand.nextInt(max - 0);
            System.out.print(mout + " ");
            i++;
          }
          while (i < matrixn);
          System.out.println();
          j++;
        }
        while (j < matrixn);

  }
}

Answer 1

需要在循环开始时重置i，否则它仍然是上一行的matrixn。

do {
    i = 0;  // It won't work without this
    do {
        Random rand = new Random();
        int mout = rand.nextInt(max - 0);
        System.out.print(mout + " ");
        i++;
    } while (i < matrixn);
    System.out.println();
    j++;
} while (j < matrixn);

虽然这可行，但使用 for 循环会更好。