Euler 24

A permutation is an ordered arrangement of objects. For the objects 0, 1 and 2, “012” is one permutation. And “201” is another.

If we make all permutations of the digits 0 to 9, and order them in alphabetical order. What permutation is number one million?

We can get all permutations of the digits using permutations() from gtools. Convert to a tibble, arrange, and then slice out the answer:

library(tidyverse)
library(gtools)
answer <- permutations(10, 10, 0:9) |> 
    as_tibble() |> 
    arrange(V1, V2, V3, V4, V5, V6, V7, V8, V9, V10) |> 
    slice(1000000) |> 
    transmute(answer = paste0(V1, V2, V3, V4, V5, V6, V7, V8, V9, V10))

## Warning: The `x` argument of `as_tibble.matrix()` must have unique column names if `.name_repair` is omitted as
## of tibble 2.0.0.
## ℹ Using compatibility `.name_repair`.
## This warning is displayed once every 8 hours.
## Call `lifecycle::last_lifecycle_warnings()` to see where this warning was generated.