Create Java Program to Find the Determinant of a Matrix

Java/Java Program to Find the Determinant of a Matrix

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+// Java program to find
+// Determinant of a matrix
+class GFG {
+
+	// Dimension of input square matrix
+	static final int N = 2;
+
+	// Function to get cofactor of
+	// mat[p][q] in temp[][]. n is
+	// current dimension of mat[][]
+	static void getCofactor(int mat[][], int temp[][],
+							int p, int q, int n)
+	{
+		int i = 0, j = 0;
+
+		// Looping for each element
+		// of the matrix
+		for (int row = 0; row < n; row++) {
+			for (int col = 0; col < n; col++) {
+				// Copying into temporary matrix
+				// only those element which are
+				// not in given row and column
+				if (row != p && col != q) {
+					temp[i][j++] = mat[row][col];
+					// Row is filled, so increase
+					// row index and reset col index
+					if (j == n - 1) {
+						j = 0;
+						i++;
+					}
+				}
+			}
+		}
+	}
+
+	/* Recursive function for finding determinant
+	of matrix. n is current dimension of mat[][]. */
+	static int determinantOfMatrix(int mat[][], int n)
+	{
+		int D = 0; // Initialize result
+
+		// Base case : if matrix
+		// contains single element
+		if (n == 1)
+			return mat[0][0];
+
+		// To store cofactors
+		int temp[][] = new int[N][N];
+
+		// To store sign multiplier
+		int sign = 1;
+
+		// Iterate for each element of first row
+		for (int f = 0; f < n; f++) {
+			// Getting Cofactor of mat[0][f]
+			getCofactor(mat, temp, 0, f, n);
+			D += sign * mat[0][f]
+				* determinantOfMatrix(temp, n - 1);
+
+			// terms are to be added
+			// with alternate sign
+			sign = -sign;
+		}
+
+		return D;
+	}
+
+	/* function for displaying the matrix */
+	static void display(int mat[][], int row, int col)
+	{
+		for (int i = 0; i < row; i++) {
+			for (int j = 0; j < col; j++)
+				System.out.print(mat[i][j]);
+
+			System.out.print("\n");
+		}
+	}
+
+	// Driver code
+	public static void main(String[] args)
+	{
+
+		int mat[][] = { { 4, 3 }, { 2, 3 } };
+
+		System.out.print("Determinant "
+						+ "of the matrix is : "
+						+ determinantOfMatrix(mat, N));
+	}
+}