# C++ Programming Code Examples

## C++ > Mathematics Code Examples

### C++ Program to Check if a Matrix is Invertible

``` C++ Program to Check if a Matrix is Invertible This is a C++ Program to check if the matrix is invertible or not. It is invertible only if its determinant is non-zero. #include<conio.h> #include<iostream> #include<math.h> using namespace std; double d = 0; double det(int n, double mat[10][10]); double det(int n, double mat[10][10]) { double submat[10][10]; if (n == 2) return ((mat[0][0] * mat[1][1]) - (mat[1][0] * mat[0][1])); else { for (int c = 0; c < n; c++) { int subi = 0; //submatrix's i value for (int i = 1; i < n; i++) { int subj = 0; for (int j = 0; j < n; j++) { if (j == c) continue; submat[subi][subj] = mat[i][j]; subj++; } subi++; } d = d + (pow(-1, c) * mat[0][c] * det(n - 1, submat)); } } return d; } int main(int argc, char **argv) { cout << "Enter the dimension of the matrix:\n"; int n; cin >> n; double mat[10][10]; cout << "Enter the elements of the matrix:\n"; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { cin >> mat[j][i]; } } if (det(n, mat) != 0) { cout << "The given matrix is invertible"; } else { cout << "The given matrix is not invertible"; } } ```