編程題目:
27.求一個3*3矩陣對角線元素之和。
示例代碼:
package program.calculation.exercise27;
import java.util.Scanner;
public class MatrixValueSum {
public static void main(String[] args) {
System.out.println("請輸入3*3的矩陣元素:");
@SuppressWarnings("resource")
Scanner scanner = new Scanner(System.in);
int[][] arr = new int[3][3];
for (int i=0; i<arr.length; i++) {
for (int j=0; j<arr[i].length; j++) {
arr[i][j] = scanner.nextInt();
}
}
matrixValueSum(arr);
}
private static void matrixValueSum(int[][] arr) {
int sum1 = 0;
int sum2 = 0;
for (int i=0; i<arr.length; i++) {
for (int j=0; j<arr[i].length; j++) {
if(i == j) {
sum1 += arr[i][j];
}
if(j == arr.length-i-1) {
sum2 += arr[i][j];
}
}
}
System.out.println("該矩陣的對角元素和分別是:"+sum1+"和"+sum2);
}
}
結果顯示: