code: public void put(int i, int j, double value) {
  
  		if (i < 0 || i >= N) throw new IllegalArgumentException("Illegal index");
  		if (j < 0 || j >= N) throw new IllegalArgumentException("Illegal index");
  
  		rows[i].put(j, value);
  	}
docs: set A[i][j] = value
  
  @param i
  @param j
  @param value