count number with continuous numbers of 1's ?

I had a matrix A=[0 0 1 1 1 1 0 0 0 1 1 0 0 1 0 0 1 0 0 0 1 1 1 0 0] like this , now I want a matrix B in which B(3)=1,next B(10)=1,B(14)=1 and similarly B(17)=1,B(21)=1 and rest are zeros means B gets value 1 when A first get 1.

Answer 1

[Stephen23]

>> B = [0,diff(A)>0]
B =
   0   0   1   0   0   0   0   0   0   1   0   0   0   1   0   0   1   0   0   0   1   0   0   0   0