Example: Check Upper Triangular Matrix in Java

// Check Upper Triangular Matrix
public class Main {
    public static void main(String[] args) {
        // Step 1: Define a sample square matrix
        int[][] matrix1 = {
            {1, 2, 3},
            {0, 4, 5},
            {0, 0, 6}
        };

        int[][] matrix2 = {
            {1, 2, 3},
            {4, 5, 6},
            {7, 8, 9}
        };

        // Step 2: Check if the matrix is square
        // For simplicity, we assume square matrices or handle non-square as not triangular
        boolean isSquare = true;
        if (matrix1.length == 0 || matrix1[0].length == 0 || matrix1.length != matrix1[0].length) {
            isSquare = false;
        }

        // Step 3: Apply the logic to check for upper triangular property
        if (!isSquare) {
            System.out.println("Matrix 1 is not a square matrix, so it cannot be triangular.");
        } else {
            boolean isUpperTriangular = true;
            for (int i = 0; i < matrix1.length; i++) {
                for (int j = 0; j < i; j++) { // Loop only for elements below the main diagonal (i > j)
                    if (matrix1[i][j] != 0) {
                        isUpperTriangular = false;
                        break; // Exit inner loop
                    }
                }
                if (!isUpperTriangular) {
                    break; // Exit outer loop
                }
            }
            System.out.println("Matrix 1 is an Upper Triangular Matrix: " + isUpperTriangular);
        }

        // Repeat for matrix2
        isSquare = true;
        if (matrix2.length == 0 || matrix2[0].length == 0 || matrix2.length != matrix2[0].length) {
            isSquare = false;
        }

        if (!isSquare) {
            System.out.println("Matrix 2 is not a square matrix, so it cannot be triangular.");
        } else {
            boolean isUpperTriangular = true;
            for (int i = 0; i < matrix2.length; i++) {
                for (int j = 0; j < i; j++) {
                    if (matrix2[i][j] != 0) {
                        isUpperTriangular = false;
                        break;
                    }
                }
                if (!isUpperTriangular) {
                    break;
                }
            }
            System.out.println("Matrix 2 is an Upper Triangular Matrix: " + isUpperTriangular);
        }
    }
}