iteration - Fast iterative calculation in a vector

Question

Suppose we have a start value S <- 10 and two vectors, i.e. x <- c(0,0,1,1,1,0,0,1,0,0) y <- c(3,1,1,2,1,2,2,1,1,2)

I have an iterative problem: Starting at index 1: Whenever there is a 1 in vector x the value of S should be decreased by the value (with same index) in y, otherwise S stays constant - the result should be

S = (10,10,9,7,6,6,6,5,5,5)

I have written a rather slow for-loop to solve this problem, but since my vectors are very large: Is there a fast and easy way to solve this problem in R?

Thank you for any answers!

Achim

question from:https://stackoverflow.com/questions/66060372/fast-iterative-calculation-in-a-vector

Answer 1

Waitting for answers