loop till condition met of swapping all repeated value of same column

hi,

i have a matrix A

A=[1  1  2
  2  2  3 
  3  3  4 
  4  5  6 
  5  6  7 
  6  7  8 
  7  6  26 
  8  26  27 
  9  27  28 
  10  28  29 
  11  29  30 
  12  30  31 
  13  31  32 
  14  32  33 
  15  25  29 ];

i want to make a loop which detect repeated values of column no. 3 then swap the repeated value of column 3 with column 2 and keep going until no repeated values in column 3

note:(i want to decide which repeated value i will fix and change the rest)

i make somthing like that

 uniqueVals = unique( l(:,3) );
 valCount = hist( l(:,3) , uniqueVals )';
  for i=1:15
     if valCount(i)==2
         A(i,[2,3])=A(i,[3,2]);   
     end
  end

but gives error cause it couldnt keep going and keep swapping after values keep change

the desired output

  B=[ 1  1  2 
  2  2  3 
  3  3  4 
  4  6  5 
  5  6  7 
  6  7  8 
  7  26  6 
  8  27  26 
  9  28  27 
  10  29  28 
  11  29  30 
  12  30  31 
  13  31  32 
  14  32  33 
  15  25  29 ];

as you can see when the detected repeated value is (29) in last row, the columns swapped at row 10 then it swapped at row 10 (so no repeated values at columns 3 as desired) then swapped at row 9 then swapped at row 8 then swapped at 7 then swapped at row 4 and when no repeated value at column the loop stops

Answer 1

[KSSV]

A=[1  1  2
  2  2  3 
  3  3  4 
  4  5  6 
  5  6  7 
  6  7  8 
  7  6  26 
  8  26  27 
  9  27  28 
  10  28  29 
  11  29  30 
  12  30  31 
  13  31  32 
  14  32  33 
  15  25  29 ];


[c,ia,ib] = unique(A(:,3)); 
Ncount = histc(A(:,3), c);


B = A ;
rep = nnz(Ncount>1) ;
for i = 1:rep
    idx = find(A(:,3)==c(Ncount==i+1)) ;
    B(idx(1),2:3) = A(idx(1),3:-1:2) ;
end

[hossam eldakroury]

i tried it but it only swapped row 10 and didnt continue to swap the rest

the result was

B =[ 1     1     2
     2     2     3
     3     3     4
     4     5     6
     5     6     7
     6     7     8
     7     6    26
     8    26    27
     9    27    28
    10    29    28
    11    29    30
    12    30    31
    13    31    32
    14    32    33
    15    25    29]

as you can see only row 10 swapped but row 9 still got (28) in column 3 which is repeated since row 10 got (28) too, i wanted to keep swapping while moving up till no repeated value in column 3.. i think a while loop would work but i dont know how to do it

i want the result to be like this

 B=[ 1  1  2 
  2  2  3 
  3  3  4 
  4  6  5 
  5  6  7 
  6  7  8 
  7  26  6 
  8  27  26 
  9  28  27 
  10  29  28 
  11  29  30 
  12  30  31 
  13  31  32 
  14  32  33 
  15  25  29 ]