Algorithm: quick sort implemented in python 算法导论 快速排序

 import random

 def partition(A, lo, hi):
     pivot_index = random.randint(lo, hi)
     pivot = A[pivot_index]
     A[pivot_index], A[hi] = A[hi], A[pivot_index]
     store_index = lo
     for i in range(lo, hi):
         if A[i] < pivot:
             A[i], A[store_index] = A[store_index], A[i]
             store_index = store_index + 1
     A[store_index], A[hi] = A[hi], A[store_index]
     return store_index

 def quicksort(A, lo, hi):
     if lo < hi:
         p = partition(A, lo, hi)
         quicksort(A, lo, p - 1)
         quicksort(A, p + 1, hi)

 if __name__ == '__main__':
     l = [random.randint(1, 113) for i in range(18)]
     print l
     quicksort(l, 0, len(l) - 1)
     print l