How do I get the maximum numbers of every "increasing pattern" in each row in a matrix?

Here is a matrix A consisting of "increasing patterns".

A=[1,2,3,1,2,3,4,1,2,1,2,3,4,1,1;1,2,1,1,2,3,1,2,3,4,1,2,3,4,5]

In each row of matrix A, all "increasing patterns" begin with 1.

Visually, all "patterns" are underlined separately below. The largest numbers in all "patterns" are in bold.

A =

1 2 3 1 2 3 4 1 2 1 2 3 4 1 1

1 2 1 1 2 3 1 2 3 4 1 2 3 4 5

How do I get B? This is, get the maximum numbers of all "patterns" in each row.

B=3 4 2 4 1 1
  2 1 3 4 5 0 
  % use zero to fuilfill matrix B to make dimensions of each row consistent

Answer 1

[Stephen23]

>> A = [1,2,3,1,2,3,4,1,2,1,2,3,4,1,1;1,2,1,1,2,3,1,2,3,4,1,2,3,4,5]
A =
   1   2   3   1   2   3   4   1   2   1   2   3   4   1   1
   1   2   1   1   2   3   1   2   3   4   1   2   3   4   5
>> X = diff(A,1,2)~=1;
>> X(:,end+1) = true;
>> B = A.*X
B =
   0   0   3   0   0   0   4   0   2   0   0   0   4   1   1
   0   2   1   0   0   3   0   0   0   4   0   0   0   0   5

[Image Analyst]

Clever! Then, to finish up, here's one way to get the final, desired output.

[rows, columns] = size(B)
numOutputColumns = max(any(B, 2))
B2 = zeros(rows, numOutputColumns);
for row = 1 : rows
	nonZeroElements = B(row,:) ~= 0;
	B2(row, 1:sum(nonZeroElements)) = B(row, nonZeroElements);
end
B = B2

You get

B =
     3     4     2     4     1     1
     2     1     3     4     5     0     

Just like you wanted.

Why do you want this thing anyway? Care to share the use case?

[Stephen23]

>> Y = B.';
>> Z = +~sort(Y==0,1);
>> Z(Z==1) = Y(Y~=0);
>> B = Z(any(Z,2),:).'
B =
   3   4   2   4   1   1
   2   1   3   4   5   0

[Linjun He]

Thank you! Clever answer!

Answer 2

[Linjun He]

A2=[A,ones(size(A,1),1)]-[ones(size(A,1),1),A]<=0
B=A2(:,2:end).*A

Here is what I get.

B =

0 0 3 0 0 0 4 0 2 0 0 0 4 1 1

0 2 1 0 0 3 0 0 0 4 0 0 0 0 5

It's not a good answer but it's ok for me.

I am still looking forward to a better answer.

[madhan ravi]

but in the orginal question your desired output is different right I mean 5 was padded with 0 at the end??

[Linjun He]

@madhan ravi

It's not a good answer but it's ok for me.

I am still looking forward to a better answer.