Hungarian Algorithm! Removing rows and comluns from matrix

Hi I don't have much experience with Matlab and I'm doing this project for school, the task is for implement the Hungarian Algorithm. I'm almost at the end but now I'm having problems with removing rows and columns. I'll put my code and an example to show, if someone could help me I would appreciate it.

Let's say I have this matrix A: 15 0 0 0; 0 50 20 25; 35 5 0 10; 0 65 50 65;

(bare in mind that ca has the positions of the columns to erase and la the positions for the rows to erase)

ca=[1 3]
la=[1]

for j=1:length(ca)
               A5=A3;
               y=0:n;
               A5(:,ca(j)-y(j))=[];

                  for i=1:length(la)

                      A5(la(i)-y(i),:)=[];
                  end
              end

What I noticed is that if I don't use the 'y' after the first loop (for j=1) it erases the right column but them the A5 matriz turns 4x3 and the third original column is now the second, so the loop ends up deleting the first and fourth rows. I tried adding y for making the second loop decrease in one value so the third column is now the second, but instead it returns

0    20    25
35     0    10
0    50    65

I can't see what is wrong. Can someone help me please?

Answer 1

[Baalzamon]

So you are after: [50, 25; 5, 10; 65,65] ?

    [nRowsA, nColsA] = size(A);
    ca = [1 3]; la = 1;

nRowsOut = nRowsA - length(la); % Result should have this many rows
nColsOut = nColsA - length(ca); % Result should have this many columns

Logical array same size as input

maskA       = true(nRowsA, nColsA); 

       1     1     1     1
       1     1     1     1
       1     1     1     1
       1     1     1     1

% Change all rows to false that are given in variable la
maskA(la,:) = false; 

       0     0     0     0
       1     1     1     1
       1     1     1     1
       1     1     1     1

% Change all cols to false that are given in variable ca     
maskA(:,ca) = false; 
     0     0     0     0
     0     1     0     1
     0     1     0     1
     0     1     0     1

% Now left with zeros for rows and columns we don't want.
trimmedA     = A(maskA); % Extract elements from A using the maskA

      50
       5
      65
      25
      10
      65

% From example there were two columns over 3 rows 
reshaped2array = reshape(trimmedA,nRowsOut, nColsOut);

      50    25
       5    10
      65    65
The arrays you see are just output from the line above it and for some clarity in what is going on.

There probably is an easier way which no doubt someone will mention...

[Ana]

Thank you so much for your help!