Quicksort pseudocode

quicksort.rb

while i < last
  pivot = myArray[last] — 4
  myArray = [3, 4, 1, 5, 7, 1, 4]
  i = 0
  p_index = 0
  
  myArray = [3, 4, 1, 5, 7, 1, 4]
  arr[i] = 3 is less than or equal to 4,
  3 will stay in its position(swapping 0 with 0)
  i = 1
  p_index = 1
  
  myArray = [3, 4, 1, 5, 7, 1, 4]
  4 is less than or equal to 4
  swap (1 with 1)
  i = 2
  p_index = 2
  
  myArray = [3, 4, 1, 5, 7, 1, 4]
  1 is less than or equal to 4
  swap (2 with 2)
  i = 3
  p_index = 3
  
  myArray = [3, 4, 1, 5, 7, 1, 4]
  5 is greater than 4
  do not swap
  i = 4
  p_index = 3
    
  myArray = [3, 4, 1, 5, 7, 1, 4]
  7 is greater than 4
  do not swap
  i = 5
  p_index = 3
    
  myArray = [3, 4, 1, 5, 7, 1, 4]
  1 is less than or equal to 4
  swap element at arr[i] 1 with element at arr[p_index] 5
  i = 6
  p_index = 4
    
  myArray = [3, 4, 1, 1, 7, 5, 4]
  i is not less than last
  p_index = 4
 
  swap element at arr[pivot] with element at p[index]
  myArray = [3, 4, 1, 1, 4, 5, 7]
end
return p_index = 4