javaa 声明一个4×5的二维数组用于存储矩阵数据。b 使用嵌套循环从键盘输入4×5矩阵的元素并将它们存储到二维数组中。c 初始化变量min为矩阵中的第一个元素初始化变量max为矩阵中的第一个元素。d 使用嵌套循环遍历二维数组比较每个元素与当前的min和max更新min和max的值以及对应的行号和列号。e 输出最小元素和最大元素的值以及它们所在的行号和列号。

a. int[][] matrix = new int[4][5];

b. Scanner scanner = new Scanner(System.in); for (int i = 0; i < matrix.length; i++) { for (int j = 0; j < matrix[i].length; j++) { System.out.print("Enter element at position (" + (i+1) + "," + (j+1) + "): "); matrix[i][j] = scanner.nextInt(); } }

c. int min = matrix[0][0]; int max = matrix[0][0]; int minRow = 0; int minCol = 0; int maxRow = 0; int maxCol = 0;

d. for (int i = 0; i < matrix.length; i++) { for (int j = 0; j < matrix[i].length; j++) { if (matrix[i][j] < min) { min = matrix[i][j]; minRow = i; minCol = j; } if (matrix[i][j] > max) { max = matrix[i][j]; maxRow = i; maxCol = j; } } }

e. System.out.println("Minimum element: " + min + " at position (" + (minRow+1) + "," + (minCol+1) + ")"); System.out.println("Maximum element: " + max + " at position (" + (maxRow+1) + "," + (maxCol+1) + ")")