a = [0 0 0 1 1 1 0 0 1 1 1 0 1 1 1 0 1 1 0];
before = [0 0 0 1 0 0 0 0 1 0 0 0 1 0 0 0 1 0 0];
after = [0 0 0 0 0 1 0 0 0 0 1 0 0 0 1 0 0 1 0];
da = [diff(a), 0];
bcheck = circshift(da > 0, 1);
acheck = da < 0;
all(bcheck == before)
all(acheck == after)
This may not cover leading and trailing zeros, though before and after zeros may not make sense in that case.
