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]
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
