1 import java.util.Scanner; 2 /** 3 * @author 冰樱梦 4 * 时间:2018年12月 5 * 题目:求矩阵主对角线元素的和 6 * 7 */ 8 public class Exercise08_02 { 9 public static void main(String[] args){ 10 Scanner input=new Scanner(System.in); 11 System.out.println("Enter the arrays row: "); 12 int row=input.nextInt(); 13 System.out.println("Enter the arrays column: "); 14 int col=input.nextInt(); 15 double[][] list=new double[row][col]; 16 for(int i=0;i<list.length;i++){ 17 for(int j=0;j<list[i].length;j++){ 18 list[i][j]=input.nextDouble(); 19 } 20 } 21 System.out.println("Sum of the elements in the major diagonal is "+sumMajorDiagonal(list)); 22 } 23 24 25 26 /** 27 * @param m 28 * @return 29 * 返回主对角线的和 30 */ 31 public static double sumMajorDiagonal(double [][] m){ 32 double total=0; 33 for(int i=0;i<m.length;i++){ 34 total+=m[i][i]; 35 } 36 return total; 37 } 38 }