# Java Program to Compute Determinant of a Matrix

This is the Java Program to Find the Modulus of a Matrix.Problem Description

Given a square matrix, find and print the modulus(determinant) of the matrix.
Example:
Matrix:
1 2 3
4 5 6
7 8 9

Output:
Modulus = 0Problem Solution

The algorithm for calculating modulus of 3*3 matrix is
x=(matrix[0][0] * (matrix[1][1] * matrix[2][2] – matrix[1][2] * matrix[2][1]));
y=(matrix[0][1] * (matrix[1][0] * matrix[2][2] – matrix[1][2] * matrix[2][0]));
z=(matrix[0][2] * (matrix[1][0] * matrix[2][1] – matrix[1][1] * matrix[2][0]));

determinant= x – y + z;Program/Source Code

Here is the source code of the Java Program to Find the Modulus of a Matrix. The program is successfully compiled and tested using IDE IntelliJ Idea in Windows 7. The program output is also shown below.

//Java Program to Find the Modulus of a

public class ModulusOfAMatrix {
// Function to read array elements and calculate the determinant
public static void main(String[] args) {
int order=3;
int[][] matrix=new int[3][3];
System.out.println("Enter the elements of 3x3 matrix");
int i,j;
for(i=0;i<matrix.length;i++){
for(j=0;j<matrix[i].length;j++){
try{
}
catch(Exception e){
return;
}
}
}
int determinant,x,y,z;
x=(matrix[0][0] * (matrix[1][1] * matrix[2][2]
- matrix[1][2] * matrix[2][1]));
y=(matrix[0][1] * (matrix[1][0] * matrix[2][2]
- matrix[1][2] * matrix[2][0]));
z=(matrix[0][2] * (matrix[1][0] * matrix[2][1]
- matrix[1][1] * matrix[2][0]));
determinant= x - y + z;
System.out.println("The modulus of the given matrix is "+ determinant);

}
}


Program Explanation

1. In function main(), a matrix is entered.
2. Then in variables x, y and z various coefficients are calculated.
3. Finally, the statement (determinant= x – y + z), calculates the determinant and it is displayed.

Time Complexity: O(1).Runtime Test Cases

Case 1 (Simple Test Case):

Enter the elements of 3x3 matrix
1
2
3
4
5
6
7
8
9
The modulus of the given matrix is 0

Case 2 (Simple Test Case - another example):

Enter the elements of 3x3 matrix
12
43
5
23
56
7
45
2
65
The modulus of the given matrix is -19598