Number guessing game:Compare numbers and position in Verilog

Question

I'm designing the number guessing game,aka mastermind,1A2B,And I'm stuck. I'm having problem with how to compare the 2 set of 4-digit numbers and output ? A ? B.

? A : when the number's position and value is correct,increase A's value,like,

1234=1234 => 4A0B,1234=1235 => 3A0B ...etc.

? B : when the numbers value is correct but position is not correct,increase B's value,like

1234=4321 =>0A4B,1234=7843 => 0A2B, 1234=5321 =>0A3B...etc.

Initially I'm thinking to compare both of them by each digit,but then when I use if-else if-else statement to describe it,no matter how I code it,it'll only compare 1 digit,even though I wrote it to compare 2-digit at once...

My biggest question is,how to compare these 2 set of 4-digit numbers and judge its position and value,then output how many A's how many B's.

Codes based on my thoughts and only able to compare 1-digit at a time,even though,I tried code it to compare 2-digit at a time...ultimate goal is to compare 2-set of 4-digit.

Disp_Save is register for saved answer ;

Segs_R is register for input display 7seg on the right-hand side.

Segs_L is register for compared result displaying 7seg on the left-hand side,default displaying 0A0b.

Css is Choosing States,in this case,Css<=0; is return to Keypad detecting state.

           if(Disp_Save[3:0]==Segs_R[3:0])
                begin
                    Segs_L<=16'h1A0b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[3:0]==Segs_R[7:4])
                begin
                    Segs_L<=16'h0A1b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[3:0]==Segs_R[11:8])
                begin
                    Segs_L<=16'h0A1b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[3:0]==Segs_R[15:12])
                begin
                    Segs_L<=16'h0A1b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[7:4]==Segs_R[7:4])
                begin
                    Segs_L<=16'h1A0b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[7:4]==Segs_R[3:0])
                begin
                    Segs_L<=16'h0A1b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[7:4]==Segs_R[11:8])
                begin
                    Segs_L<=16'h0A1b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[7:4]==Segs_R[15:12])
                begin
                    Segs_L<=16'h0A1b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[11:8]==Segs_R[11:8])
                begin
                    Segs_L<=16'h1A0b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[11:8]==Segs_R[3:0])
                begin
                    Segs_L<=16'h0A1b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[11:8]==Segs_R[7:4])
                begin
                    Segs_L<=16'h0A1b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[11:8]==Segs_R[15:12])
                begin
                    Segs_L<=16'h0A1b;
                    Segs_R<=16'h0;
                    Css<=0;
                end             
            else if(Disp_Save[15:12]==Segs_R[15:12])
                begin
                    Segs_L<=16'h1A0b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[15:12]==Segs_R[3:0])
                begin
                    Segs_L<=16'h0A1b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[15:12]==Segs_R[7:4])
                begin
                    Segs_L<=16'h0A1b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[15:12]==Segs_R[11:8])
                begin
                    Segs_L<=16'h0A1b;
                    Segs_R<=16'h0;
                    Css<=0;
                end

            else if(Disp_Save[3:0]==Segs_R[3:0] && Disp_Save[7:4]==Segs_R[7:4])
                begin
                    Segs_L<=16'h2A0b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[7:4]==Segs_R[3:0] && Disp_Save[3:0]==Segs_R[7:4])
                begin
                    Segs_L<=16'h0A2b;
                    Segs_R<=16'h0;
                    Css<=0;
                end
            else if(Disp_Save[3:0]==Segs_R[11:8] && Disp_Save[7:4]==Segs_R[15:12])
                begin
                    Segs_L<=16'h0A2b;
                    Segs_R<=16'h0;
                    Css<=0;
                end     

            else
                begin
                    Segs_L<=16'h0A0b;
                    Segs_R<=16'h0;
                    Css<=0;
                end

Answer 1

This isn't a full answer since it is homework. Basically, for each of the four input pairs, you will need an A output and a B output. They need to be four separate bits each. Then for the final output you need to add up the number of A's and the number of B's. I don't see any addition in your code yet, and it looks like all of the comparisons are changing a single result instead of four separate results.

A bit more detail trying to clear up some confusion. Here is some pseudo-code showing the basic structure:

// digit 0
if (input_0 == goal_0)
    A0 = 1
    B0 = 0
else
    A0 = 0
    if (input_0 == goal_1 or input_0 == goal_2 or input_0 == goal_3)
        B0 = 1
    else
        B0 = 0

// digit 1
if (input_1 == goal_1)
    A1 = 1
    B1 = 0
else
    A1 = 0
    if (input_1 == goal_0 or input_1 == goal_2 or input_1 == goal_3)
        B1 = 1
    else
        B1 = 0

// ...
// similarly for digits 2 and 3

// add up results
total_A = A0 + A1 + A2 + A3
total_B = B0 + B1 + B2 + B3