Matrix to string, filled with zeros

I have a question about transforming a matrix. I have a matrix that looks something like this:

A = [9998; 9999; 0; 1; 2; ...... 9997; 9998; 9999; 0; 1; 2]

I want to turn this matrix into a string which contains always 4 elements:

B = ['9998'; '9999'; '0000'; '0001'; '0002'; ..... '9997'; '9998'; '9999'; '0000'; '0001'; '0002']

Then I also want to create a matrix (preferably without a loop) that adds 1 every time the number jumps down from 9999 to 0:

C = [0; 0; 1; 1; 1; 1; 1; 1; ..... 1; 1; 1; 2; 2; 2]

Answer 1

[dpb]

>> string(num2str(A,'%04d')).'
ans = 
  1×11 string array
    "9998"    "9999"    "0000"    "0001"    "0002"    "9997"    "9998"    "9999"    "0000"    "0001"    "0002"
>> cumsum([0 diff(A.')<0])
ans =
     0     0     1     1     1     1     1     1     2     2     2
>> 

[dpb]

compose was what was trying to remember was called but didn't at the time...I'd suggest a combination solution of Matt's in lieu of num2str

Answer 2

[Matt J]

B=compose('%.4d',A);

C=cumsum( A(2:end)==0 & A(1:end-1)==9999 );