DeterminantOfMatrix.java

packagecom.thealgorithms.maths;

/*
 * @author Ojasva Jain
 * Determinant of a Matrix Wikipedia link: https://en.wikipedia.org/wiki/Determinant
 */
publicfinalclassDeterminantOfMatrix {
privateDeterminantOfMatrix() {
 }

/**
 * Calculates the determinant of a given matrix.
 *
 * @param a the input matrix
 * @param n the size of the matrix
 * @return the determinant of the matrix
 */
staticintdeterminant(int[][] a, intn) {
intdet = 0;
intsign = 1;
intp = 0;
intq = 0;
if (n == 1) {
det = a[0][0];
 } else {
int[][] b = newint[n - 1][n - 1];
for (intx = 0; x < n; x++) {
p = 0;
q = 0;
for (inti = 1; i < n; i++) {
for (intj = 0; j < n; j++) {
if (j != x) {
b[p][q++] = a[i][j];
if (q % (n - 1) == 0) {
p++;
q = 0;
 }
 }
 }
 }
det = det + a[0][x] * determinant(b, n - 1) * sign;
sign = -sign;
 }
 }
returndet;
 }
}