Generating combination of binary numbers

Question

Luqman Saleem 2019-12-18

评论： Luqman Saleem 2019-12-18

Variable N and M are some integers and

. I want to create permutation of M 1s and

0s in the order shown below. Let

and

A = [1 1 0 0 0;
0 1 0 0;
0 0 1 0;
0 0 0 1;
1 1 0 0;
1 0 1 0;
1 0 0 1;
0 1 1 0;
0 1 0 1;
0 0 1 1];

Note that in first row all 1s are on right side, then in next row the right most 1 move one step toward right and so on...

Answer 1

Guillaume 2019-12-18

nchoosek outputs the indices in your desired ordering, so it's easy:

N = 5, M = 2;  %demo data
cols = nchoosek(1:N, M);
A = zeros(size(cols, 1), N);
A(sub2ind(size(A), repmat((1:size(A, 1))', 1, M), cols)) = 1

Luqman Saleem 2019-12-18

Wow! That was very quick. Slute!

I am so noob in programming.