how i can put the (-1) in binary matrix with condition ?

how i can put (-1) after and before any group of ones in matrix like this

before code A = [ 1 1 0 0 0 1 0 1 1 
                  0 1 1 0 0 0 0 1 1
                  0 0 1 1 0 0 1 0 0 ]

after code A* = [ 1  1 -1  0 -1  1 -1  1  1
                 -1  1  1 -1  0  0 -1  1  1 
                  0 -1  1  1 -1 -1  1 -1 -1 ]

[Azzi Abdelmalek]

The last value of A* is not correct

Answer 1

[Azzi Abdelmalek]

A = [ 1 1 0 0 0 1 0 1 1 
      0 1 1 0 0 0 0 1 1
      0 0 1 1 0 0 1 0 0 ]
for k=1:size(A,1);
 id_before=strfind(A(k,:),[0 1])
 id_after=strfind(A(k,:),[1 0])+1
 A(k,[id_before id_after])=-1
end

Answer 2

[Kuifeng]

 % is the last number in your A* equal to 0 instead?
%the following code may work
[rows cols] =  size(A);
A_diff = A(:,1:end-1)-A(:, 2:end);
A(find(A_diff == -1)) = -1;
A(find(A_diff == 1)+rows) = -1;