A quicksort implementation to sort an array without using conventional functions.

quicksort.R

"
A quicksort implementation to sort an array without using conventional functions.

It has two phases and it's a divide and conquer approach:
- partition phase
- sort phase

There is a nice video that demonstrates this concept using 
Hungarian dance at https://www.youtube.com/watch?v=ywWBy6J5gz8
"

sort_vect <- function(vect) {
  "
  Sorts a vector recursively using the quicksort algorithm.
  "
  if (length(vect)) {
    
    # Gets a random element because using the first one is less effective
    pivot <- sample(vect, 1)
    
    # Picks the values smaller and bigger than the pivot, the partition phase
    lower <- vect[vect < pivot]
    upper <- vect[vect > pivot]
    
    # This deals with cases where the pivot is repeated
    pivots <- vect[vect == pivot]
    
    return(c(sort_vect(lower), pivots, sort_vect(upper)))
  }
}