66. Demultiplexer

How do you plan to solve it?

/*Write your code here*/
module demux1to4 (
    input d,
    input [1:0] s,
    output reg [3:0] y
);

always @ (*) begin
    case(s)
    2'b00: y = {3'b000,d};
    2'b01: y = {2'b00,d,1'b0}; 
    2'b10: y = {1'b0,d,2'b00}; 
    2'b11: y = {d,3'b000};
    default: y = 4'd0;
    endcase
end
endmodule