SUDOKU SOLVER

Augusto Mazzei
/
SUDOKU SOLVER
on 8 Nov 2023
10
34
0
1
1950
clear all,drawframe(25);
Write your drawframe function below
function drawframe(f)
persistent data
if isempty(data)
    %__matrix S initialized randomly___
    S=zeros(9);
    for m=1:16
        x = randi(9,1,2);
        val = setdiff(1:9,[S(x(1),:) S(:,x(2))']);
        S(x(1),x(2))=val(randi(length(val)));
    end
    %____________________________________
    G=[];
    Sdue=[];
    p=perms(1:9);
    data.prems = find(S);
    coop=[-2 -1;1 2;-1 1;]; 
    cur=ones(1,9); 
    act=1;
    solveSudo()
    data.S = S;
end
drawNum(data,min(9,f-10))
function solveSudo(varargin)
        G=getGroups;
        G(2,:)=G(1,:);
        if all(~cellfun(@isempty,G))
            S(S==0)=nan; 
            Sdue=S;
            while act<10
                SetRaw
            end
        else
            disp("!")
        end
    end
    function G=getGroups
        G=cell(1,9);
        Sn=S;
        Sn(Sn==0)=nan;
        for i=1:9
            A=p;
            idx=find(S(i,:));
            for j=1:length(idx)
                A=A(A(:,idx(j))==S(i,idx(j)),:);
            end
            rig=1:9; rig(i)=[];
            num=Sn(rig,:);
            C=zeros(size(A,1),9,size(num,1));
            for kk=1:size(num,1)
                C(:,:,kk)=A~=num(kk,:);
            end
            idx=all(all(C,3),2);
            A=A(idx,:);
            B = Sn(i+coop(1+rem(i,3),:),:);
            B=[ B(1:2,[2 3 1 5 6 4 8 9 7]);
            B(1:2,[3 1 2 6 4 5 9 7 8])];
            C=zeros(size(A,1),9,size(B,1));
            for jj=1:size(B,1)
                C(:,:,jj)= A~=B(jj,:) ;
            end
            idx = all(all(C,3),2);
            A=A(idx,:);
            G{i} = A;
        end
    end
function SetRaw
    i = cur(act);
    try
        rr = G{2,act}(i,:);
        S(act,:)=rr;
        act = act+1;
        cur(act)=1;
        newG
    catch
        cur(act)=1;
        S(act:end,:)=Sdue(act:end,:);
        act = act-1;
        cur(act)=cur(act)+1;
    end
end
    function newG
        if act<10
            A = G{1,act};
            B=S(1:act-1,:);
            C=zeros(size(A,1),9,size(B,1));
            for j=1:size(B,1)
                C(:,:,j)=A~=B(j,:);
            end
            idx=all(all(C,3),2);
            A=A(idx,:);
            switch rem(act,3)
                case 2
                    B=S(act-1,:);
                    B=[B(1,[2 3 1 5 6 4 8 9 7]);
                    B(1,[3 1 2 6 4 5 9 7 8])];
                    C=zeros(size(A,1),9,size(B,1));
                    for j=1:size(B,1)
                        C(:,:,j) = A~=B(j,:);
                    end
                    idx = all(all(C,3),2);
                    A=A(idx,:);
                case 0
                    B=S(act-[1 2],:);
                    B=[B(1:2,[2 3 1 5 6 4 8 9 7]);
                    B(1:2,[3 1 2 6 4 5 9 7 8])];
                    C=zeros(size(A,1),9,size(B,1));
                    for j=1:size(B,1)
                        C(:,:,j)=A~=B(j,:);
                    end
                    idx=all(all(C,3),2);
                    A=A(idx,:);
                otherwise
            end
            G{2,act}=A;
        end
    end
end
function drawNum(data,f)
    hold off
    for ii=0:9
        plot([0 9]+0.5,-[ii ii]-0.5,'-k','LineW',1+(~rem(ii,3)));
        hold on
        plot([ii ii]+0.5,-[0 9]-0.5,'-k','LineW',1+(~rem(ii,3)));
    end
    axis square
    axis off
    for i=1:81
        [r,c]=ind2sub([9 9],i);
        co = 'none';
        if any(data.prems==i)
        co='r';
        elseif r <= f
        co = 'k';
        end
        text(c,-r,""+data.S(i),'Color',co,'FontW','bold','hor','center');
    end
    drawnow
end
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SUDOKU SOLVER
Augusto Mazzei