7-5 编程练习题答案

import java.util.Scanner;

public class Test
{
	public static void main(String[] args)
	{
		Scanner input = new Scanner(System.in);
		double[][] matrix1 = new double[3][3];
		double[][] matrix2 = new double[3][3];
		
		System.out.print("Enter matrix1: ");
		for(int i = 0; i < matrix1.length; i++)
			for(int j = 0; j < matrix1[i].length; j++)
				matrix1[i][j] = input.nextDouble();
	
		System.out.print("Enter matrix2: ");
		for(int i = 0; i < matrix2.length; i++)
			for(int j = 0; j < matrix2[i].length; j++)
				matrix2[i][j] = input.nextDouble();
		
		double[][] answers = caculate(matrix1, matrix2);

		System.out.println("The matrices are added as follows; ");
		System.out.println(matrix1[0][0] + " " + matrix1[0][1] + " " + matrix1[0][2] + "     " + matrix2[0][0] + " " + matrix2[0][1] + " " + matrix2[0][2] + "     " + answers[0][0] + " " + answers[0][1] + " " + answers[0][2]);
		System.out.println(matrix1[1][0] + " " + matrix1[1][1] + " " + matrix1[1][2] + "  +  " + matrix2[1][0] + " " + matrix2[1][1] + " " + matrix2[1][2] + "  =  " + answers[1][0] + " " + answers[1][1] + " " + answers[1][2]);
		System.out.println(matrix1[2][0] + " " + matrix1[2][1] + " " + matrix1[2][2] + "     " + matrix2[2][0] + " " + matrix2[2][1] + " " + matrix2[2][2] + "     " + answers[2][0] + " " + answers[2][1] + " " + answers[2][2]);
/*		System.out.printf("%.1f %.1f %.1f     %.1f %.1f %.1f     %.1f %.1f %.1f\n", matrix1[0][0], matrix1[0][1], matrix1[0][2], matrix2[0][0], matrix2[0][1], matrix2[0][2], answers[0][0], answers[0][1], answers[0][2]);
		System.out.printf("%.1f %.1f %.1f  +  %.1f %.1f %.1f  =  %.1f %.1f %.1f\n", matrix1[1][0], matrix1[1][1], matrix1[1][2], matrix2[1][0], matrix2[1][1], matrix2[1][2], answers[1][0], answers[1][1], answers[1][2]);
		System.out.printf("%.1f %.1f %.1f     %.1f %.1f %.1f     %.1f %.1f %.1f\n", matrix1[2][0], matrix1[2][1], matrix1[2][2], matrix2[2][0], matrix2[2][1], matrix2[2][2], answers[2][0], answers[2][1], answers[2][2]);
*/	}

	public static double[][] caculate(double[][] matrix1, double[][] matrix2)
	{
		double[][] answers = new double[matrix1.length][matrix1[0].length];
		
		for(int i = 0; i < answers.length; i++)
			for(int j = 0; j < answers[i].length; j++)
				answers[i][j] = matrix1[i][j] + matrix2[i][j];

		return answers;
	}
}