How to append vectors to a list group by group

Question

I want to add some vectors to a list, and I want to that show like this:

1.1
2.1 2
3.1 2 10
4.1 10
5.2
6.2 10
7.10

this is my code:

subsets <- function(s) {
    res <- list()
    n <- length(s)
    s <- sort(s)
    help <- function(temp, index, res) {
        tmp <- temp
        
        res <- append(res, tmp)
        i <- index
        
        while (i < n + 1 ) {
            temp <- append(temp, s[i])
            res <- help(temp, i + 1, res)
            temp <- temp[-length(temp)]
            i <- i + 1
        }
        return(res)
    }
    res <- help(c(), 1, res)
    return(res)
}


s <- c(1, 10, 2)
subsets(s)

the output is:

1.1
2.1
3.2
4.1
5.2
6.10
7.1
8.10
9.2
10.2
11.10
12.10

Could somebody do me a favor? I am a new man for R, and I don't know what should I do...

Answer 1

If you want your vectors to be in a list, you can use unlist:

unlist(list)
# [1]  1  1  2  1  2 10  1 10  2  2 10 10

Or add as.list if you want everything in a list of one item:

as.list(unlist(list))

[[1]]
[1] 1

[[2]]
[1] 1

[[3]]
[1] 2

[[4]]
[1] 1

[[5]]
[1] 2

[[6]]
[1] 10

[[7]]
[1] 1

[[8]]
[1] 10

[[9]]
[1] 2

[[10]]
[1] 2

[[11]]
[1] 10

[[12]]
[1] 10