MATLAB: Finding the first zero element in a row and fill the entire row with the last non zero element

MATLABmatrixmatrix manipulation

I have an m*n matrix which has only zeros and natural numbers. If there is a zero in a row, all the remaining elements after the first zero are also zeros. I would like to replace all zero elements with the last non zero element in the row. I am looking for the fastest way to do it in Matlab. Is there anyway without a loop? if not, what is the best way? Thanks.
For example:
A = [1 3 1 0 0 0 0; 
     1 4 2 1 3 4 1; 
     2 3 1 2 3 3 0];
% and I would like to have
B = [1 3 1 1 1 1 1; 
     1 4 2 1 3 4 1; 
     2 3 1 2 3 3 3];

Best Answer

>> A = [1,3,1,0,0,0,0;1,4,2,1,3,4,1;2,3,1,2,3,3,0]
A =
   1     3     1     0     0     0     0
   1     4     2     1     3     4     1
   2     3     1     2     3     3     0
>> A(:,2:end) = A(:,2:end) - cumsum(diff(A,1,2).*(A(:,2:end)==0),2)
A =
   1     3     1     1     1     1     1
   1     4     2     1     3     4     1
   2     3     1     2     3     3     3
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