In this article, we will understand how to display an upper triangular matrix. The matrix has a row and column arrangement of its elements. A matrix with m rows and n columns can be called as m × n matrix. An upper triangular matrix is a triangular matrix with all elements below the main diagonal are 0.
Below is a demonstration of the same −
Suppose our input is −
The matrix is defined as: 2 1 4 1 2 3 3 6 2
The desired output would be −
The upper triangular matrix is: 2 1 4 0 2 3 0 0 2
Algorithm
Step 1 - START Step 2 - Declare an integer matrix namely input_matrix. Step 3 - Define the values. Step 4 - Iterate over each element of the matrix using two for-loops, assign 0 to all the [i][j] positions that comes below the diagonal of the matrix using rows != column condition. Step 5 - Display the matrix as result Step 6 - Stop
Example 1
Here, we bind all the operations together under the ‘main’ function.
public class UpperTriangle { public static void upper_triangular_matrix(int input_matrix[][]) { } public static void main(String[] args) { int input_matrix[][] = { { 2, 1, 4 }, { 1, 2, 3 }, { 3, 6, 2 } }; int rows = input_matrix.length; int column = input_matrix[0].length; System.out.println("The matrix is defined as: "); for (int i = 0; i < rows; i++) { for (int j = 0; j < column; j++) { System.out.print(input_matrix[i][j] + " "); } System.out.println(); } if (rows != column) { return; } else { for (int i = 0; i < rows; i++) { for (int j = 0; j < column; j++) { if (i > j) { input_matrix[i][j] = 0; } } } System.out.println("\nThe upper triangular matrix is: "); for (int i = 0; i < rows; i++) { for (int j = 0; j < column; j++) { System.out.print(input_matrix[i][j] + " "); } System.out.println(); } } } }
Output
The matrix is defined as: 2 1 4 1 2 3 3 6 2 The upper triangular matrix is: 2 1 4 0 2 3 0 0 2
Example 2
Here, we encapsulate the operations into functions exhibiting object-oriented programming.
public class UpperTriangle { public static void upper_triangular_matrix(int input_matrix[][]) { int rows = input_matrix.length; int column = input_matrix[0].length; if (rows != column) { return; } else { for (int i = 0; i < rows; i++) { for (int j = 0; j < column; j++) { if (i > j) { input_matrix[i][j] = 0; } } } System.out.println("\nThe upper triangular matrix is: "); for (int i = 0; i < rows; i++) { for (int j = 0; j < column; j++) { System.out.print(input_matrix[i][j] + " "); } System.out.println(); } } } public static void main(String[] args) { int input_matrix[][] = { { 2, 1, 4 }, { 1, 2, 3 }, { 3, 6, 2 } }; int rows = input_matrix.length; int column = input_matrix[0].length; System.out.println("The matrix is defined as: "); for (int i = 0; i < rows; i++) { for (int j = 0; j < column; j++) { System.out.print(input_matrix[i][j] + " "); } System.out.println(); } upper_triangular_matrix(input_matrix); } }
Output
The matrix is defined as: 2 1 4 1 2 3 3 6 2 The upper triangular matrix is: 2 1 4 0 2 3 0 0 2