Check and replace elements in a matrix

I have a random generated matrix (2x8) which consist of zeros and ones. How can I check, in each row, if there are 2 ones in the first 4 elements and 1 one in the last 4 elements ? Moreover, If there are more ones than the prescribed, I would like to exchange the redundants ones with zeros.

      i.e rand = ( 1 1 1 0  0 1 1 0; 0 1 1 1  0 1 0 0 )

 modified_rand = ( 1 1 0 0  0 1 0 0; 0 1 1 0  0 1 0 0 )

Any help could be useful. Thanks in advance !

Answer 1

[Azzi Abdelmalek]

a=[ 1 1 1 0  0 1 1 0; 0 1 1 1  0 1 0 0 ]
a1=a(:,1:4);
a2=a(:,5:end)
a1(cumsum(a1,2)>2)=0
a2(cumsum(a2,2)>1)=0
b=[a1 a2]

[Konstantinos]

Thanks a lot!

[Konstantinos]

If there are more ones than the prescribed number, is it possible to find random which ones to keep and which ones to replace with zeros ?