java第二周作业--实现矩阵的加法和乘法运算

实现矩阵对角线的加法和乘法运算

 

//数组的对角线求出行数和列数相等矩阵的非对角线元素之和，矩阵用二维数组表示。package shiyan;import  java.util.*;public class Shiyan3_12 {public static void main(String[] args) {Shiyan3_12  s=new Shiyan3_12();        }   public  Shiyan3_12()   {   Scanner sca=new Scanner(System.in);   System.out.println("请输入选择：");   System.out.println("1.实现矩阵的加法");   System.out.println("2.实现矩阵的乘法");   int a=sca.nextInt();   switch(a)   {   case 1:jia();break;   case 2: cheng();break;   default:break;   }   }  public  void jia()  {    int  sum=0;Scanner sca=new Scanner(System.in);int[][] b = null;System.out.println("行数和列数:");int a=sca.nextInt();b=new int[a][a];System.out.println("输入数据"+a+"行"+a+"列");int n=0;for(int i=0;i<a;i++){for(int j=0;j<a;j++){b[i][j]=sca.nextInt();}}System.out.println("数组：");for(int i=0;i<a;i++){for(int j=0;j<a;j++){System.out.print(b[i][j]+"  ");n++;}if(n%a==0){System.out.println();}}     for(int i=0;i<a;i++){for(int j=0;j<a;j++){if(i==j||i+j==a-1){  sum=sum+b[i][j]; }}}     System.out.println("对角线之和：");  System.out.println(sum);        }  public  void cheng()  {  int  sum=1;Scanner sca=new Scanner(System.in);int[][] b = null;System.out.println("行数和列数:");int a=sca.nextInt();b=new int[a][a];System.out.println("输入数据"+a+"行"+a+"列");int n=0;for(int i=0;i<a;i++){for(int j=0;j<a;j++){b[i][j]=sca.nextInt();}}System.out.println("数组：");for(int i=0;i<a;i++){for(int j=0;j<a;j++){System.out.print(b[i][j]+"  ");n++;}if(n%a==0){System.out.println();}}     for(int i=0;i<a;i++){for(int j=0;j<a;j++){if(i==j||i+j==a-1){  sum=sum*b[i][j]; }}}     System.out.println("对角线之乘：");  System.out.println(sum);         }}