MIT-Curricular/OOP/Java/Lab/Week4/TraceNorm.java

import java.util.Scanner;

class TraceNorm {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter the size of the square matrix: ");
        int n = sc.nextInt();

        double[][] matrix = new double[n][n];

        System.out.println("Enter the elements of the matrix:");
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                System.out.print(
                    "Enter the element at (" + i + "," + j + "): "
                );
                matrix[i][j] = sc.nextInt();
            }
        }

        // trace
        double trace = 0;
        for (int i = 0; i < n; i++) {
            trace += matrix[i][i];
        }

        // norm
        double normSquared = 0;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                normSquared += matrix[i][j] * matrix[i][j];
            }
        }
        double norm = Math.sqrt(normSquared);

        System.out.println("Trace of the matrix: " + trace);
        System.out.println("Norm of the matrix: " + norm);

        sc.close();
    }
}