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84 lines
2.7 KiB
Java
84 lines
2.7 KiB
Java
/*
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This is the java program to check whether the matrix is invertible or not. The square matrix is invertible if and only if its determinant is non zero.
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*/
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//This is a simple program to check whether the matrix is invertible or not.
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//The complexity of the algorithm is O(n^3)
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import java.util.*;
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public class Invertible_Matrix
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{
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public double determinant(double A[][],int N)
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{
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double det=0;
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if(N == 1)
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{
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det = A[0][0];
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}
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else if (N == 2)
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{
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det = A[0][0]*A[1][1] - A[1][0]*A[0][1];
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}
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else
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{
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det=0;
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for(int j1=0; j1<N; j1++)
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{
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double[][] m = new double[N-1][];
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for(int k=0; k<(N-1); k++)
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{
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m[k] = new double[N-1];
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}
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for(int i=1; i<N; i++)
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{
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int j2=0;
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for(int j=0; j<N; j++)
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{
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if(j == j1)
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continue;
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m[i-1][j2] = A[i][j];
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j2++;
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}
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}
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det += Math.pow(-1.0,1.0+j1+1.0)* A[0][j1] * determinant(m,N-1);
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}
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}
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return det;
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}
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public static void main(String args[])
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{
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Scanner input = new Scanner(System.in);
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System.out.println("Enter the order of the square matrix");
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int n = input.nextInt();
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System.out.println("Enter the elements of the square matrix");
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double[][] mat = new double[n][n];
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for(int i=0; i<n; i++)
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{
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for(int j=0; j<n; j++)
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{
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mat[i][j] = input.nextDouble();
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}
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}
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Invertible_Matrix I = new Invertible_Matrix();
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if(I.determinant(mat, n) == 0)
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{
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System.out.println("Matrix is not Invertible, as the determinant is : "+I.determinant(mat, n));
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}
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else
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{
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System.out.println("Matrix is Invertible, as the determinant is : "+I.determinant(mat, n));
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}
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input.close();
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}
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}
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/*
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Enter the order of the square matrix:
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3
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Enter the elements of the square matrix:
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1 2 3
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4 5 6
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7 8 9
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Matrix is not Invertible, as the determinant is : 0.0 |