Menu
I am totally new to python and I am trying to implement quicksort in it. Could someone please help me complete my code?
I do not know how to concatenate the three arrays and printing them.
def sort(array=[12,4,5,6,7,3,1,15]): less = [] equal = [] greater = [] if len(array) > 1: pivot = array[0] for x in array: if x < pivot: less.append(x) if x == pivot: equal.append(x) if x > pivot: greater.append(x) sort(less) sort(pivot) sort(greater) 
378
Quicksort is not very practical in Python since our builtin timsort algorithm is quite efficient, and we have recursion limits. We would expect to sort lists in-place with list. sort or create new sorted lists with sorted - both of which take a key and reverse argument.
Divide and conquer: Quicksort splits the array into smaller arrays until it ends up with an empty array, or one that has only one element, before recursively sorting the larger arrays. In place: Quicksort doesn't create any copies of the array or any of its subarrays.
A best sorting algorithm in python The time complexity of quicksort is O(n log n) in the best case, O(n log n) in the average case, and O(n^2) in the worst case. Quicksort is also considered as the ” fastest” sorting algorithm because it has the best performance in the average case for most inputs.
def sort(array=[12,4,5,6,7,3,1,15]): """Sort the array by using quicksort.""" less = [] equal = [] greater = [] if len(array) > 1: pivot = array[0] for x in array: if x < pivot: less.append(x) elif x == pivot: equal.append(x) elif x > pivot: greater.append(x) # Don't forget to return something! return sort(less)+equal+sort(greater) # Just use the + operator to join lists # Note that you want equal ^^^^^ not pivot else: # You need to handle the part at the end of the recursion - when you only have one element in your array, just return the array. return array Quick sort without additional memory (in place)
Usage:
array = [97, 200, 100, 101, 211, 107] quicksort(array) print(array) # array -> [97, 100, 101, 107, 200, 211] def partition(array, begin, end): pivot = begin for i in range(begin+1, end+1): if array[i] <= array[begin]: pivot += 1 array[i], array[pivot] = array[pivot], array[i] array[pivot], array[begin] = array[begin], array[pivot] return pivot def quicksort(array, begin=0, end=None): if end is None: end = len(array) - 1 def _quicksort(array, begin, end): if begin >= end: return pivot = partition(array, begin, end) _quicksort(array, begin, pivot-1) _quicksort(array, pivot+1, end) return _quicksort(array, begin, end) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
