17. Binary to Gray Code Converter

How do you plan to solve it?

module bin2gray4(
    input [3:0] bin_in,
    output reg [3:0] gray_out
);

// 1st approach 
    // assign gray_out = bin_in ^ (bin_in >> 1);

// 2nd approach
integer i;

always @(*) begin
gray_out[3] = bin_in[3];
for (i = 3; i > 0; i = i - 1) begin
    gray_out[i-1] = bin_in[i] ^ bin_in[i-1];
end
end

endmodule