public int[][] solver(int[][] matrix) {
		HashSet<Integer> x = new HashSet<Integer>();
		HashSet<Integer> y = new HashSet<Integer>();
		
		for (int i = 0; i < matrix.length; i++)
		{
			for (int j = 0; j < matrix[i].length; j++)
			{
				if (matrix[i][j] == 0)
				{
					if (!x.contains(i))
						x.add(i);
					if (!y.contains(j))
						y.add(j);
				}
			}
		}
		
		for (int i = 0; i < matrix.length; i++)
		{
			for (int j = 0; j < matrix[i].length; j++)
			{
				if (x.contains(i) || y.contains(j))
				{
					matrix[i][j] = 0;
				}
			}
		}
		
		return matrix;
	}