如何替换矩阵内的元素？

Question

我的输入元素是 0 或 1...我想用 I 替换 1，用 N 替换 0。

目前我可以读取和输出元素，如何用 I 和 N 替换和输出

        System.out.println("Enter the elements of the matrix");
        for (i = 0; i < m; i++)
            for (j = 0; j < n; j++)
                first[i][j] = in.nextInt();

        // Display the elements of the matrix
        System.out.println("Elements of the matrix are");
        for (i = 0; i < m; i++) {
            for (j = 0; j < n; j++)
                System.out.print(first[i][j] + "\n");

由于我是 java 新手，任何帮助将不胜感激。谢谢！

Answer 1

由于您想将数字替换为字符，因此矩阵数据类型应为char。这是一个例子：

int m = 3, n = 3;
char[][] matrix = new char[m][n];
Scanner scan = new Scanner(System.in);
System.out.println("Enter the elements of the matrix");
for (int i = 0; i < m; i++)
     for (int j = 0; j < n; j++)
          matrix[i][j] = scan.next().charAt(0);
for(int i = 0; i < matrix.length; i++)
    for(int j = 0; j < matrix[i].length; j++)
        if(matrix[i][j]=='1') 
            matrix[i][j] = 'I';
        else if(matrix[i][j]=='0')
            matrix[i][j] = 'N';
System.out.println(Arrays.deepToString(matrix));

示例输入/输出：

Enter the elements of the matrix
1
1
1
0
0
0
1
0
1
[[I, I, I], [N, N, N], [I, N, I]]

根据您的要求，这里是您如何扫描xxx xxx xxx xxx 形式的字符，其中x 应该是0 或1，并根据m 和n 写入：

int m = 4, n = 3;
Scanner scan = new Scanner(System.in);
System.out.println("Enter the elements of the matrix");
StringBuilder sb = new StringBuilder();
for (int i = 0; i < m; i++) {
    String inp = scan.nextLine();
    while (inp.length() != n || !inp.matches("[01]+")) {
        System.out.println("Warning: input must be "+n+" characters and only 1 or 0.");
        inp = scan.nextLine();
    }
    sb.append(inp+" ");
}
String str = sb.toString().trim().replaceAll("1", "I");
str = str.replaceAll("0", "N");
System.out.println(str);

示例输入/输出：

Enter the elements of the matrix
112
Warning: input must be 3 characters and only 1 or 0.
111
000
101
010
III NNN INI NIN