經典排序演算法的Python實現

標籤：find   new   快速排序   element   case   bsp   sele   range   python   

 

一、選擇排序select_sort

# Finds the smallest value in an arraydef findSmallest(arr):  # Stores the smallest value  smallest = arr[0]  # Stores the index of the smallest value  smallest_index = 0  for i in range(1, len(arr)):    if arr[i] < smallest:      smallest = arr[i]      smallest_index = i  return smallest_index# Sort arraydef selectionSort(arr):  newArr = []  for i in range(len(arr)):      # Finds the smallest element in the array and adds it to the new array      smallest = findSmallest(arr)      newArr.append(arr.pop(smallest))  return newArrprint selectionSort([5, 3, 6, 2, 10])

 

 

一、快速排序quick_sort

def quicksort(array):  if len(array) < 2:    # base case, arrays with 0 or 1 element are already "sorted"    return array  else:    # recursive case    pivot = array[0]    # sub-array of all the elements less than the pivot    less = [i for i in array[1:] if i <= pivot]    # sub-array of all the elements greater than the pivot    greater = [i for i in array[1:] if i > pivot]    return quicksort(less) + [pivot] + quicksort(greater)print quicksort([10, 5, 2, 3])

 

經典排序演算法的Python實現