Sequence of win streaks [duplicate]

Question

I'm trying to calculate a sequence of win streaks for a binary vector. Given a vector

set.seed(2)
x <- sample(c(0,1), 10, replace = TRUE)
[1] 0 1 1 0 1 1 0 1 0 1

I want to calculate the cumulative sum of ones with a "reset" every time there's a zero. So, in this case, the output of the function should be

[1] 0 1 2 0 1 2 0 1 0 1

What's the easiest way to do this on R?

Answer 1

We can use ave and create a grouping variable with cumsum at every occurrence of 0 in the vector and count the consecutive numbers without 0 in each group.

ave(x, cumsum(x==0), FUN = seq_along) - 1
#[1] 0 1 2 0 1 2 0 1 0 1