Compute the matrix multiplication of two matrices

prod_mat.java

class prod_mat {
  public static void main(String[] args) {
    int [][] a = {
                  {5,1},
                  {2,3},
                  {3,4}
                 };
    int [][] b = {
                  {1,2,0},
                  {4,3,-1}
                 };

    // a is a matrix of type (m,n)
    // b is a matrix of type (n,p)
    int m = a.length;
    if (a[0].length != b.length)
      throw new Error("Les deux matrices ne sont pas compatibles !");
    int n = a[0].length;
    int p = b[0].length;

    // c hold the matrix multiplication
    // so c is of type (m,p)
    int [][] c = new int[m][p];

    int i,j,k;
    int prod;

    for (k=0; k<n; k++) {
      for (i=0; i<m; i++) {
        for (j=0; j<p; j++) {
          c[i][j] += a[i][k] * b[k][j];
        }
      }
    }

    // display result
    for (i=0; i<m; i++) {
      for (j=0; j<p; j++) {
        System.out.print(c[i][j] + " ");
      }
      System.out.println();
    }

  }
}