MATLAB: How to store ” first_element ” values

for looplooploopsmatricessave

Could you please tell how to store the "first_element" values in a matrix?
%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%code
first_element = [];
end_element = [];
A = [ 1 1 1 1 2 3 4 4 4 ; 1 2 3 4 5 5 5 5 5];
 for this_row = A.'
V = this_row'; 
X = diff(V)~=0;
B = find([true,X]);
E = find([X,true]);
D = 1+E-B ;
first_element = D(1,1)
end_element = D(end);
end
%%%%%%%%%%%%%%%%%%%%
output of the following code is :
first_element =
     4
first_element =
    1
But I want output to be :
first_element = [ 4 ; 1]
%%%%%%%%%%%%%%%%%%%%%%%%%
Thanks

Best Answer

A = [ 1 1 1 1 2 3 4 4 4 ; 1 2 3 4 5 5 5 5 5];
[first_element,end_element] = deal(zeros(size(A,1),1)); % preallocate
for k = 1:size(A,1)
    V = A(k,:);
    X = diff(V)~=0;
    B = find([true,X]);
    E = find([X,true]);
    D = 1+E-B ;
    first_element(k) = D(1,1);
    end_element(k) = D(end);
end
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