How to delete rows in matrix, where a value is repeated 3 times or more!

I have the matrix like this:

b =[

1 1 3 6 6 6 6; 1 1 3 6 6 6 7; 1 1 3 6 6 6 8; 1 1 3 6 6 6 9;

1 1 3 6 6 7 7; 1 1 3 6 6 7 8; 1 1 3 6 6 7 9; 1 1 3 6 6 8 8;

1 1 3 6 6 8 9; 1 1 3 6 6 9 9; 1 1 3 6 7 7 7]

I would like to remove all rows, where any value is repeated more than twice. In case of this matrix the rows 1,2,3,4 and 11 should be removed.

Answer 1

[Awais Saeed]

b =[ 1 1 3 6 6 6 6; 1 1 3 6 6 6 7; 1 1 3 6 6 6 8; 1 1 3 6 6 6 9;
     1 1 3 6 6 7 7; 1 1 3 6 6 7 8; 1 1 3 6 6 7 9; 1 1 3 6 6 8 8;
     1 1 3 6 6 8 9; 1 1 3 6 6 9 9; 1 1 3 6 7 7 7]

b = 11×7

1 1 3 6 6 6 6 1 1 3 6 6 6 7 1 1 3 6 6 6 8 1 1 3 6 6 6 9 1 1 3 6 6 7 7 1 1 3 6 6 7 8 1 1 3 6 6 7 9 1 1 3 6 6 8 8 1 1 3 6 6 8 9 1 1 3 6 6 9 9

delRow = [];
for row = 1:1:size(b,1)
    x = b(row,:);
    [~,~, counts] = unique(x);
    counts = accumarray(counts,1).';
    if (max(counts)>=3)             % if number is repeated more than twice then
        delRow = [delRow row];      % save row numbers and delete them later
    end
end
b(delRow,:)=[] % delete those row now

b = 6×7

1 1 3 6 6 7 7 1 1 3 6 6 7 8 1 1 3 6 6 7 9 1 1 3 6 6 8 8 1 1 3 6 6 8 9 1 1 3 6 6 9 9

[Danilo Korze]

Works perfectly, thank you very much!