Remove the air bubbles

Given a matrix a, return a matrix b in which all the zeros have "bubbled" to the top. That is, any zeros in a given column should be moved to the top. The order of the remaining nonzero numbers in the column should be preserved.

Input a = [ 1 2 3

                  0 4 5

                  6 0 0 ]

Output b is [ 0 0 0

                     1 2 3

                      6 4 5 ]

MATLAB CODE:

clc

x=input('Enter the matrix:');

[r c]=size(x);

zo=[];

for j=1:c

    Y=[];

    for i=1:r

        Y=[Y x(i,j)];

    end

     d=0;

        for u=1:r

            if(Y(u)==0)

                d=d+1;

            end

        end

        t=[];

        for rp=1:d

            t=[t 0];

        end

        for h=1:r

            if(Y(h)~=0)

                t=[t Y(h)];

            end

        end

        zo=[zo t'];

end

disp(zo);

Explanation:

        

Sample Output:

Function:

function zo = bubbles(x)

[r c]=size(x);
zo=[];
for j=1:c
Y=[];
for i=1:r
Y=[Y x(i,j)];
end
d=0;
for u=1:r
if(Y(u)==0)
d=d+1;
end
end
t=[];
for rp=1:d
t=[t 0];
end
for h=1:r
if(Y(h)~=0)
t=[t Y(h)];
end
end
zo=[zo t'];
end


end